PHILADELPHIA -- Nobody really knows where Adam Haseley will be in a few years, or how good he will be.

But the Phillies naturally are confident that Haseley -- selected with the eighth overall pick in the 2017 Draft -- will be a good big leaguer, and they signed him to a $5.1 million signing bonus on Wednesday. He will begin his professional career on Friday in Clearwater, Fla., and after getting in baseball shape, he could begin play with Class A Williamsport.

Some scouts think Haseley could move quickly through the Minor Leagues.

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"Personally, I don't really like putting deadlines and expectations on myself," Haseley said. "I'm just going to continue to try to do what I did this spring, and the things I learned, I'm going to try to keep working on those things and bury my head and see what happens."

Haseley, 21, hit .390 with 16 doubles, one triple, 14 home runs, 56 RBIs, a .491 on-base percentage and a .659 slugging percentage in 58 games in his junior season with the University of Virginia. He also went 7-1 with a 3.58 ERA in 11 starts, but his future with the Phillies is in the outfield.

"It will be different," Haseley said about focusing on hitting and playing the outfield. "Just from a health perspective, it will be a lot easier to recover, especially days after pitching. I'm usually pretty sore the day after. From a strength perspective, I'll be able to do different lifts that will help my overall strength."

And that is why the Phillies are so optimistic that Haseley will live up to the expectations of a No. 8 pick: He will be concentrating on one thing instead of two.

"He's made progressions," said Phillies area scout Paul Murphy, who saw Haseley 35 to 40 times over the years. "The fact that he pitches -- and the last offseason was the first time he trained as a hitter -- it really leads you to believe that the best days are ahead of him if he just concentrates on hitting. So he made a big jump this season with his power numbers. He's got some projection left to his body. He's going to get bigger and stronger. We're getting a great makeup kid from a good college baseball program. It's very exciting. I think he's going to be a really good Phillie for a long time."

Murphy said that Haseley reminds him a bit of Nick Markakis .

"But really, I wouldn't limit him to anyone, because I don't know if he's going to be the same player you see today," he said. "For a college junior, he has a chance to get a lot bigger and stronger. He has a chance to keep improving. Sometimes you'll take an older college player, and that's what he is. He's not going to get any better. With the pitching and the fact that he's got room to add weight and still mature, he has a chance to be a better player than he is today. And he's a pretty good player today."

The Phillies have also signed right-hander Spencer Howard (second round), third baseman Jake Scheiner (fourth), shortstop Nick Maton (seventh), left-hander Jhordany Mezquita (eighth), third baseman Jack Zoellner (ninth) and right-hander Connor Brogdon (10th). Howard signed for $1.15 million, less than the $1,523,800 suggested slot value for pick No. 45, according to MLB.com's Jim Callis.

Todd Zolecki has covered the Phillies since 2003, and for MLB.com since 2009. Follow him on Twitter and Facebook and listen to his podcast.