Representatives from four NFL teams were present at Illinois State's pro day on Wednesday, when 21 players worked out outdoors on FieldTurf. Two Redbirds prospects are potential free-agent pickups for teams following the conclusion of the . Offensive lineman Jermaine Barton (6-foot-6 5/8, 332 pounds) could not work out at the pro day because of a left knee operation that took place in February. Barton has nearly 36-inch arms. Some team will come back and take a long look at Barton either before the draft or after (as a free-agent po sibility) to see if the knee is healthy. Because of his length -- scouts drool over big offensive line prospects with long arms -- a team will see if it can make a developmental project out of him. Barton began his Serge Ibaka Jersey college football career at Miami (Fla.) and was there for two seasons (including a redshirt season) before transferring to Illinois State. He went to powerhouse St. Thomas Aquinas in Fort Lauderdale, Fla. and was a three-star recruit. He was high school teammates with of the , of the , of the and of the . Offensive lineman Michael Liedtke (6-3 3/4, 305) ran the 40-yard dash in 4.91 and 4.93 seconds. He had a 33-inch vertical jump and 9-foot-4 broad jump. He had a 20-yard short shuttle time of 4.94 seconds and a three-cone time of 7.35 seconds. He performed 28 reps of 225 pounds on the bench pre s. Liedtke was probably a better lineman that Barton during his time at Illinois State, but because of Barton's size (Liedtke has 33 1/8-inch arms) he is viewed as having better long-range NFL potential. Follow Gil Brandt on Twitter _ _. Jay Scrubb Jersey