Leading up to when the first pick by the Philadelphia Phillies is announced by Commissioner Rob Manfred shortly after 7 ET tonight, Jim Callis and Jonathan Mayo will be working the phones, texting and emailing decision-makers in the scouting industry, as they try to line up their final mock Drafts. Along the way, they hear a lot of rumors, buzz, talk of guys with helium and guys sliding. They will bring that information to everyone here in MLBPipeline.com's Draft Buzz.

Will a workout decide who's No. 1?

Sometimes the last impression is the most important one.

Players who are in line to be selected starting tonight have all obviously been scouted for a long time. Evaluations for this year's Draft started in earnest last summer, with follow lists generated from showcases and summer leagues.

Players expected to be taken in the top couple of rounds are seen by multiple levels of scouts, from area guys to cross-checkers to scouting directors and even general managers. All of that information is used to line up a board. But a player can really help himself with what is often the last look a team has: a private workout.

Teams will bring several players into their home ballpark to let them throw a bullpen session or take batting practice and infield/outfield. Back in 2012, the Astros felt extremely comfortable with taking Carlos Correa because he wowed them in such a pre-Draft workout.

Complete 2016 Draft coverage

This year, the Phillies are still grappling with who to take No. 1 overall. In our latest mock drafts, both Jim Callis and I selected California high-school outfielder Mickey Moniak as our choice for that spot. But there was late buzz that Kyle Lewis, from Mercer, had become a more serious candidate. The reason? A very impressive workout for the Phillies' decision-makers on Monday.

Philadelphia continues to work on finding that talent/value balance, hoping to get the most bang for their buck. Lewis' last impression will undoubtedly be in their evaluators' minds as they do so.

-- Jonathan Mayo

Phillies still mulling; Lewis gaining steam

With less than 24 hours remaining before the Phillies exercise the No. 1 overall pick in the 2016 Draft, there didn't seem to be a decision as to who that player will be.

While Florida left-hander A.J. Puk and California high school outfielder Mickey Moniak have been the front-runners in recent weeks, Mercer outfielder Kyle Lewis is generating increased buzz for the top spot today. Other players, such as Louisville outfielder Corey Ray, also could be in the mix, though Puk, Moniak and Lewis remain the favorites.

The uncertainty at the top reflects the lack of a transcendent talent in the Draft. Though Puk can unleash mid-90s fastball and wipeout sliders, he also has had a history of inconsistency with the Gators. Moniak is a lock to remain in center field in a down year for up-the-middle players, but he might not have a true impact bat. With Lewis, there are questions about his busy right-handed swing and his small-college competition.

-- Jim Callis

How Perez news will affect his landing spot

As news spread about the reports of shortstop prospect Delvin Perez's failed drug test, teams were scrambling to figure out if they would consider the Puerto Rican high schooler should he get to them at various points of the first round.

Perez, ranked No. 9 on MLBPipeline.com's Top 200 Draft Prospects list, had been considered a sure-fire top 10 pick. He was being discussed as high as No. 2 (Reds), and most frequently mentioned at No. 5 (Milwaukee) or No. 8 (San Diego). The positive drug test, reportedly for a performance-enhancer, has thrown Perez's Draft status completely up in the air.

Several teams said they would no longer consider taking Perez, especially those picking in the upper part of the first round. Not every team in the top 15 or so picks had ruled him out completely, with discussions about taking him likely to continue until today. Any team interested in taking Perez would likely have to involve ownership in making such a decision.

Teams lower in the first round might have much more interest, thinking they could get a special talent at a discount, one they never thought they had a chance of considering. A scouting exec in the middle of the round stated that his team was discussing Perez, but that he fell in the "makes us nervous" category. Another scouting director picking in the bottom half of the round said that it is "tough to get that talent where we pick."

Questions will most certainly have to be answered before deciding to take Perez, but even if he slides out of the top 10, it does seem likely that he will still hear his name called at some point in the first round.

-- Jonathan Mayo

Signability concerns

As always, teams will weigh ability against signability when making picks at the top of the Draft. Two days before the Draft begins, six potential first-round talents stand out as the toughest signs.

Listed in order of their ranking on MLBPipeline.com's Draft Top 200, they are:

Blake Rutherford, OF, Chaminade Prep (Canoga Park, Calif.), No. 8. He entered the year as the top-rated high school position prospect but had a good but not great senior season. Teams also don't love the fact that Rutherford turned 19 a month before the Draft, and now he has no obvious home in the first 10 selections. No specific price tag has been circulated, but the feeling is that he'll want at least $3 million to give up his UCLA scholarship.

Matt Manning, RHP, Sheldon HS (Sacramento, Calif.), No. 11. The son of former NBA player Rich Manning, he has boosted his stock this spring more than any of the top high school arms. He also has the opportunity to play both baseball and basketball at Loyola Marymount -- and a reported asking price of $5 million to give that up.

Joey Wentz, LHP, Shawnee Mission East HS (Prairie Village, Kan.), No. 16. Our No. 6-rated high school pitcher in a Draft deep in them, Wentz saw his velocity drop off slightly at the end of his senior season after he missed much of 2015 with a dead arm. To forgo his commitment to Virginia, he wants top-10-pick money. The assigned value for the 10th selection is $3,380,600.

Jared Horn, RHP, Vintage HS (Napa, Calif.), No. 34. Yet another prep pitcher, Horn has a big league body and athleticism, not to mention a fastball that has hit 97 mph. Now that he has raised his profile this spring, it will take $3 million to lure him away from a California scholarship

Drew Mendoza, 3B, Lake Minneola HS (Minneola, Fla.), No. 36. He's one of the best all-around hitters in the Draft and may be the toughest sign in this group. Clubs think negotiations will start at at least $3 million and aren't sure even that will be enough to pry him away from attending Florida State.

Will Benson, OF, The Westminster Schools (Atlanta), No. 38. Like Rutherford, Benson is a tooled-up high school outfielder whom scouts expected more from this spring. Word is that his family wants the same $4 million bonus that fellow Georgia prep outfielder Daz Cameron got from the Astros as a supplemental first-rounder a year ago.

How much these signability questions are born of a desire to attend college vs. an attempt at Draft gamesmanship remains to be seen. The Phillies, Reds and Braves have the three largest bonus pools as well as the first three selections, none of whom will sign for full pick value. Cincinnati (Nos. 35 and 43), Atlanta (Nos. 40 and 44) and Philadelphia (No. 42) all have picks soon after the first round and will be in position to pay those players more than they would get if they were drafted where they fit based solely on talent.

Along the same lines, Barnegat (N.J.) High left-hander Jason Groome's switching of his college commitment from Vanderbilt to Chipola (Fla.) JC can be read in two ways. It could be seen as a sign that MLBPipeline's top-rated prospect will be more signable because he has less leverage without the Commodores, who keep many of their best recruits. It also could be interpreted that he'll be less signable because he could re-enter the 2017 Draft after his freshman season at Chipola.

-- Jim Callis

Groome to JUCO?

Jason Groome, ranked No. 1 on the Top 200 Draft Prospects list, might be headed to junior college, if the Draft doesn't go as planned.

Groome, the lefty from Barnegat Township High School in New Jersey, had originally committed to Vanderbilt University, but there was late word that he had changed gears and instead committed to Chipola College, a two-year school in Florida. By switching to the junior college, Groome would be eligible for the 2017 Draft should he decide not to sign.

As the spring started, that did not seem like a possibility, as Groome appeared to be a top-of-the-Draft type of player, one even in consideration to be taken No. 1 overall. But it's been an uneven year for Groome, and there have been concerns about his makeup that are seemingly causing the southpaw to slide. And the fact that he has reportedly floated a $4 million bonus demand could possibly scare off some teams that pick later.

In April, Groome was ruled ineligible for 30 games by the New Jersey State Interscholastic Athletic Association for violating its transfer rule. The 17-year-old had spent his junior season at IMG Academy in Bradenton, Fla., then transferred back to Barnegat. Because IMG Academy is a boarding school, the NJSIAA ruled Groome's return home did not constitute a change of address.

If Groome's signing demands don't match the potential post-slide landing spots, he could decide to roll the dice, pitch a year back in Florida and try his luck in the Draft again next year.

Of course, this could all be a negotiating ploy to create more leverage for Groome leading up to today.

-- Jonathan Mayo

Braves looking for deal at No. 3?

With this Draft class, particularly at the top, very much in flux, teams picking in the Top 10 are still trying to figure out how things will line up. Starting with the Phillies, who are still reportedly considering several options with the top selection, the volatility is causing teams picking early to explore any and all options.

That includes potential bargains. The Atlanta Braves have the No. 3 pick and have mostly been associated with taking a bat with the pick. The last few mocks on MLBPipeline.com have had Atlanta taking local Mercer product Kyle Lewis at No. 3. And there would be interest in Florida lefty A.J. Puk should he get to the Braves. One thing there doesn't seem to be is consensus, about both who will be there and who the Braves will take.

As a result, the Braves -- like most of the teams in the top third of the first round -- are looking at potential bargains with their first pick. There has been a good amount of buzz about them looking at high school arms for a while. That intensified about one player in particular when they had a large presence at Ian Anderson's last start in upstate New York.

Anderson, ranked No. 13 in the Top 200, didn't hurt his cause any by throwing his fastball in the 94-97 mph range and striking out 16 in the start, cementing his status in the first round. The Braves do have extra picks, with a Lottery Round A pick at No. 40, acquired via a trade with the Marlins, then their second-round pick at No. 44. If they save money at No. 3, they could be more aggressive about going after talent that slid because of signability concerns later on.

The talk surrounding Anderson was that the Vanderbilt commit had told teams he was looking for $3 million. Pick value for the No. 3 selection is slightly more than $6.5 million. The Braves could potentially meet Anderson's asking price and still have $3.5 million and change to play with in later rounds.

That all sounds like an intriguing scenario, but it is one that still seems like a bit of a long shot. But it's one the Braves can't rule out because of the uncertainty at the top.

-- Jonathan Mayo

Dunn on the rise

At the start of the college season, Boston College right-hander Justin Dunn was a reliever scouts thought about giving a chance to start at the next level. When he was moved into his college rotation, it was as if a wish had been granted by the scouting genie. Dunn hasn't disappointed since the move, either, giving him as much helium as any college pitcher in the Draft class.

Dunn is ranked No. 29 in the Top 200, but there seems like there is no doubt he'll go much higher than that. Since starting for the first time on April 9, Dunn has made eight appearances (including that first start), seven of them as a starter. The Eagles won seven of those games and Dunn posted a 1.34 ERA in 47 innings.

He's saved his best for last, in pressure situations, with a lot of people watching. First came his complete-game victory (with nine strikeouts) against Georgia Tech on May 21, his last regular season start. Then, last Friday, he beat Tulane in Regional play by striking out 11 over seven innings to help BC on its way to an improbable Super Regional appearance.

Dunn was already firmly planted in the first round. By showing what he can do with his four-pitch mix when stretched out as a starter, his stock has taken off, with his name coming up as high as the No. 11 pick.

-- Jonathan Mayo