Colts unearthed Marlon Mack, but defensive picks have been mixed bag

Here's a look at the first half impact of the Indianapolis Colts' draft class:

Malik Hooker, S, first round: The former Ohio State standout was on his way to having an impressive rookie season until he suffered a torn ACL and MCL in Week 7. Hooker, despite dealing with injuries most of the offseason and training camp, finished his first season with three interceptions, which still leads the team. He'll be the Colts' starting free safety for years to come once he returns from the knee injury. Grade: Out for season

Quincy Wilson, CB, second round: Wilson has been a mystery all season. He had an impressive Week 2 performance against Arizona and then was inactive for six straight weeks. Three of those weeks were due to a knee injury, but he was a healthy inactive the other three weeks. Wilson’s poor practice habits have caused the coaching staff to turn sour on him despite him being one of the team’s top three cornerbacks. Grade: Below average

Tarell Basham, DE, third round: It took eight weeks for Basham to have a memorable play despite the Colts’ desperate need for pass-rushers. He recorded his first sack against the Cincinnati Bengals. Basham has only three tackles even though he has been active in seven of the team’s eight games this season. Grade: Below average

Marlon Mack, RB, fourth round: Speed, speed and more speed. That’s the best way to describe what Mack has given the Colts this season. He has three touchdowns and seven rushing or receiving plays of at least 20 yards this season. His workload has increased in recent weeks after Robert Turbin was lost for the season because of an elbow injury. A strong rest of the season will put Mack in a good position to be the Colts' starting running back next season. Grade: Above average

Grover Stewart DT, fourth round: Stewart is in a tough position because the strongest part of the Colts' defense has been the line with Al Woods and Johnathan Hankins anchoring the middle. Stewart, in his limited playing time, has six tackles. Grade: Below average

Nate Hairston, CB, fifth round: Hairston has spent the season as the team’s primary slot cornerback. Defensive coordinator Ted Monachino has used Hairston at times in their blitz packages. Hairston has two sacks, which is third on the team, and two passes defended. It would help Hairston if he also was able to play cornerback on the outside, a position in which the Colts have dealt with some injuries. Grade: Average

Anthony Walker Jr., LB, fifth round: Walker was supposed to be in the mix for significant snaps at middle linebacker. But he has spent most of the season dealing with a hamstring injury. He has been inactive for six of the eight games. Grade: Incomplete