BOURBONNAIS, Ill. -- Although it's believed Corey Wootton could return from a knee injury in time for the regular season opener, the next few weeks provide the Chicago Bears coaching staff a chance to evaluate defensive ends further down the depth chart.

Defensive ends Mario Addison and Vernon Gholston, in particular, are seeing increased practice reps with Wootton currently on the shelf.

"No. 78 [Addison] is getting a little look, I like his movement," Bears defensive coordinator Rod Marinelli said. "Vernon is getting some more reps."

Addison, an undrafted rookie free agent out of Troy, appears to be putting together a solid training camp. He registered a tackle for a loss and a quarterback hit in the Bears' preseason opener against the Buffalo Bills on Saturday.

"Everybody is doing a good job," Bears starting defensive end Julius Peppers said. "Mario is doing well, he's coming on. We have guys that need to step up with Corey being out, so guys are going to get a lot of time to make an impression. He's taking advantage."

Gholston's struggles in three years with the New York Jets are well documented, and although the former first-round pick hasn't exactly stood out at camp like Addison, Marinelli says he's starting to see small improvements from Gholston in practice.

"I think he's gotten better every single (day)," Marinelli said. "(It's) small things, not a gigantic leap, it's small things from his takeoff to what he's looking at. I thought his best day of practice was [Wednesday]. Sometimes you won't see it because it's the little things, but I think he is progressing. (We) just got to stay positive with him, believe in him and it will come."

One reason Gholston landed in Chicago after being waived by the Jets is because the Bears envisioned him as a better fit in a 4-3 defense, as opposed to the 3-4 scheme run in New York. It doesn't sound as if Gholston's transition has been seamless by any stretch of the imagination, but the defensive end believes he's making improvements to his game.

"It's one of those things where you look at it for what it is," Gholston said. "I'm two weeks maybe into practice, so you say, shoot, if you look at it day by day you kind of get down on yourself. But you can say it's only been two weeks, so imagine another two weeks and another two weeks from there. So that's what you got to keep focusing on."