LAKE FOREST, Ill. -- Based on the organized team activities (OTA) portion of the Chicago Bears' offseason program, rookie fourth-round pick Brock Vereen looks to be a serious contender to earn a permanent place in the starting lineup.

Bears safety Brock Vereen, who participated in the team's rookie minicamp in May, is adjusting to playing in the NFL. Nam Y. Huh/AP Photo

Vereen took all the first-team reps at safety alongside free-agent signee Ryan Mundy on Wednesday, as veterans Chris Conte and Craig Steltz continue to be sidelined due to injuries. M.D. Jennings and Danny McCray handled the reps on the second team.

"I wouldn't say [I'm] shocked [by the starters reps], but I know nothing is set," Vereen said. "I'm just coming in and working hard. If that gets me on the field, then so be it.

"It's really starting to slow down for me out there. Now I'm able to react rather than to have to think about it."

Vereen played multiple defensive back positions in college for Minnesota, but appears best suited to line up at free safety in the NFL. Mundy is built like a strong safety at 6-foot-1, 209 pounds, but the safety spots are generally viewed as interchangeable.

Here are other observations from Wednesday's OTA, the final session open to the media:

• With Matt Slauson still recovering from shoulder surgery, Brian de la Puente worked with the starters at left guard. Many consider de la Puente to be the heir apparent to Roberto Garza at center, although the former New Orleans Saints starter signed only a one-year contract with the Bears in the offseason.

• Cornerback Charles Tillman and defensive tackle Jeremiah Ratliff were present this week after being absent from last week's open OTA to the media.

• The Bears' trio of linebackers in their base defense during the majority of team drills consisted of D.J. Williams (MLB), Lance Briggs (WLB) and Shea McClellin (SLB). However, both Williams and McClellin came off the field in the nickel package in favor of Jon Bostic.

• Rookie first-round draft choice Kyle Fuller continued to run with the No. 1's in nickel as Tim Jennings mainly bumped inside to cover the slot with Tillman at the opposite cornerback spot.

• Jay Cutler connected with Brandon Marshall and Marquess Wilson in the end zone on back-to-back passes during a red zone drill. Marshall did have a couple drops over the course of the afternoon.

• Marshall did return a punt at one point on Wednesday.

• Reserve quarterback Jerrod Johnson saw action on special teams when he lined up as one of the two cornerbacks tasked with slowing down the gunner on punt return. Hard to remember a quarterback wearing the orange "off-limits" jersey ever participating on special teams before. But Johnson held up just fine during the drill and flashed some impressive speed trailing the gunner down the field.

• New quarterback Jimmy Clausen received fewer reps than Johnson and rookie David Fales, but the former Carolina Panther had some zip on the ball and seemed to have a decent understanding of the offense whenever he went under center.

• The Bears have one final OTA scheduled for Thursday in advance of the club's three-day veteran minicamp next week. Cutler is expected to meet the media next Tuesday for the first time since the start of the offseason in April.