When the Chicago Bears brought in CB Jonathan Wilhite and Kelvin Hayden, it looked like Tim Jennings' days could be numbered as a starter -- and maybe a Bear.

Instead, Jennings made a commitment to get better at making plays on the ball -- a shortcoming last year that cost him his starting spot near season's end. Jennings had a huge offseason with 10 INTs at OTAs or minicamp and has been making plays all over the field in scrimmage, even at 5-foot-8 against 6-5 Brandon Marshall. Tuesday, Jennings knocked a pass 15 yards downfield from Marshall and also stole a short one for an INT after Marshall bobbled it, then took it to the end zone.

"He’s not the tallest corner in the league, but he plays big, he plays tall, he’s tough, and he’s got good hands," coach Lovie Smith said. 

Jennings always had been considered a solid tackler and run-support player.

"As a cornerback, it’s going to come down to a one-on-one situation, eventually, where you have to make the play," Smith said. "Tim having a chance to go against Brandon Marshall, Devin (Hester), Alshon Jeffery, those guys, is making him better."

Auspicious debut: First-round draft pick Shea McClellin was down on himself after Sunday's practice but had problems again Tuesday. In two-on-two pass rush drills, he got stood up, bent backwards and fell back to the turf while going against T Tyler Hendrickson, a 6-8, 313-pound undrafted free agent from Concordia of Minnesota.

Injury update: WR Eric Weems got shaken up early in practice and returned, but only on a limited basis.

He said it: WR Brandon Marshall had some wondering if he was rookie WR Alshon Jeffery's agent after praising him so lavishly. "Honestly, we just finished watching film, and I'm actually learning from Alshon," Marshall said. "Things that he was able to do (vs.) press (coverage) these past few days I wasn't able to do when I first came in the NFL. I'm picking up on things now."

Follow Bears reporter Gene Chamberlain on Twitter @CBSSportsNFLCHI.