The Indianapolis Colts today begin their rookie mini-camp, where they will have their eight draft picks, their 21 signed undrafted free agents, and several other tryout players in the building and on the field working on learning the basics of the system and showing what they can do on the field.

It's a chance for the rookies to get acclimated to the Colts and, for many of these players, a chance to catch the eye of the coaches. There are a lot of very intriguing players signed by the Colts in the post-draft process, and you can find the complete list here. There's always one or two undrafted players who make the roster for the Colts, which means that these players are certainly ones worth monitoring. Let's take a look at just a few of those guys who are worth keeping an eye on.

Ron Thompson, linebacker, Syracuse

If there was any question about Ron Thompson being a player to watch, that should have been erased by the fact that the Colts gave him a $15,000 signing bonus to sign - signifying both that he's a good player and was likely a sought-after free agent. During his time at Syracuse, Thompson (6-3, 255 pounds) played in 37 games (starting 24) and recorded 87 tackles, 12 sacks, 21 tackles for loss, six forced fumbles, and a fumble recovery. In 2015, Thompson led his team with seven sacks. His decision to leave school early for the NFL had much to do with changes in the coaching staff, and he was projected to be a sixth round pick by CBS. NFL.com's Gil Brandt actually had him ranked as his 101st best prospect in the draft. His ability as a pass rusher were evident at times at Syracuse, and for a team like the Colts desperately needing help in that area, it makes sense for them to bring him in. The Colts list him at linebacker, and he likely will occupy the edge rusher outside linebacker spot as he works to make the roster. With how desperately the Colts need to find young pass rush help, any edge rusher brought in this offseason will be worth paying attention to, but Ron Thompson stands out among the rest of the undrafted free agent class as one in particular to pay attention to.

Curt Maggitt, linebacker, Tennessee

Another talented player signed as an undrafted free agent by the Colts is Curt Maggitt, who also is listed as a linebacker by Indianapolis. His on-field talent is well thought of, and last offseason CBS Sports' Rob Rang even included him as a first round pick in a way-too-early mock draft (before the 2015 season took place). While at Tennessee, Maggitt (6-3, 246 pounds) played in 35 games and started 12 of them, recording 141 tackles, 13.5 sacks, 28.5 tackles for loss, four forced fumbles, and a pass defensed. He missed all but two games in his senior season due to a hip injury, but in 2014 he recorded a very impressive eleven sacks and 15 tackles for loss - including four multiple-sack games. The injury in 2015 hurt his draft stock some, as did an off-the-field incident, as Maggitt was accused of punching a teammate in the locker room. Those factors pushed him down in the draft to the late-round range, but he wound up going undrafted. He figures to be an outside linebacker in the Colts' system, but he possesses skill against both the pass and the run. He has the ability to get after the quarterback but also to defend against the run, giving him versatility and making him a very interesting name to keep an eye on as we move forward this offseason and into training camp.

Josh Ferguson, running back, Illinois

As we said with Ron Thompson, money talks, and the Colts gave Josh Ferguson some money that raises some eyebrows: a $10,000 signing bonus and $25,000 guaranteed. That's not common for undrafted free agents, so that alone warrants keeping a closer eye on the back. His play on the field does too, however. Playing in 47 games at Illinois, Ferguson (5-10, 200 pounds) rushed for 2,586 yards and 18 touchdowns while averaging 5.1 yards per carry, caught 168 passes for 1,507 yards and eight scores, and added 21 kickoff returns for 381 yards. In total, he accounted for 4,474 all-purpose yards, good for the second-most in school history. He also holds the Illinois records for career receptions and receiving yards by a running back, and at the end of the 2015 season was the only active FBS player with 2,500+ career rushing yards and 1,500+ career receiving yards. According to Pro Football Focus, he forced a missed tackle once every 4.4 carries, the ninth-best mark in the running back class. He was projected to be a fifth or sixth round pick by most outlets, so seeing him go undrafted was a bit of a surprise. The Colts are looking for help at running back and surprisingly didn't add one in the draft and only brought in one undrafted running back: Josh Ferguson. The team is looking for depth spots and every spot besides the starting one is open, so it's very possible that we could see Ferguson make the roster.

Tevaun Smith, wide receiver, Iowa

Tevaun Smith didn't have the most impressive stats at Iowa, but he certainly is an intriguing prospect. The 6-2, 205 pound receiver caught 102 passes for 1,500 yards and seven touchdowns in 47 career games (starting 24), averaging 14.7 yards per catch. As a senior in 2015, he caught 32 passes for 563 yards and ten scores in 12 games (10 starts), and in 2014 he was named Honorable Mention All-Big Ten after catching 43 passes for 596 yards and three touchdowns. He really caught some eyes at his pro day, where he ran a 4.38 40 yard dash - which would have ranked third among wide receivers at this year's Scouting Combine. He was primarily a deep threat at Iowa and was dangerous in that area, though he still has work to do in other areas to round out his game as an overall receiver. He does have the potential to carve out a role with some team (whether now or in the future) if he can continue to work on some things, which makes him a nice undrafted signing. The Colts could really use some wide receiver depth after T.Y. Hilton, Donte Moncrief, and Phillip Dorsett, as there really isn't any guy after those three that seems guaranteed of a depth receiver spot. That leaves the door wide open for an undrafted free agent to take one of those spots, and Tevaun Smith would figure to be a guy to look out for at the position.

Darion Griswold, tight end, Arkansas State

There are several other players who could be included in this list so this shouldn't be viewed as comprehensive, but the last guy we'll look at is tight end Darion Griswold. The 6-5, 264 pound tight end played in 50 games at Arkansas State, catching 65 passes for 892 yards and nine scores, averaging 13.7 yards per catch. There's nothing overly impressive about those numbers, but he's still learning the tight end position after arriving at Arkansas State as a quarterback. His size and athleticism makes him an intriguing player to NFL teams as a tight end, and he's still got room to grow in learning the details of the position. He was used primarily as a blocker at Arkansas State, though he does have potential in the passing game as well. The Colts do have a roster spot open at tight end, after Dwayne Allen and Jack Doyle as the top two guys at the position. There are players who will be competing for the spot, but the Colts may like a guy with Griswold's size and potential. If he impresses this offseason and in camp, there's a spot available for him to win.