LAKE FOREST, Ill. – Wide receiver Markus Wheaton is such a mystery to the Chicago Bears that offensive coordinator Dowell Loggains had to search the archives to figure out how Wheaton can help the vertical passing attack.

“Markus has been here, but we don’t have a lot of exposure with him because he was hurt in OTAs and hurt in training camp and obviously he’s missed a couple weeks,” Loggains said on Wednesday. “We’re trying to figure out still where exactly he is, what exactly he’s good at. We have to rely a lot on the 2015 tape when you evaluate him because he missed some time in 2016.”

Wheaton signed a two-year deal with Chicago in the offseason that guaranteed him $6 million in 2017, but Wheaton has just one catch for 18 yards after battling a litany of injuries dating to training camp.

Wheaton, who appeared in only three games for the Steelers in 2016 because of injuries, underwent an emergency appendectomy the first week of training camp in Bourbonnais and later had surgery to repair a fractured pinkie finger.

The broken finger knocked Wheaton out of the first two weeks of the regular season, but he returned for Weeks 3-6 before tearing a groin muscle at practice prior to the Bears game at Baltimore on Oct. 16.

Wheaton said he anticipates playing on Sunday against Green Bay, but no one really knows what to expect.

Wheaton – on the rare occasions he was healthy – mostly caught balls from former starting quarterback Mike Glennon, not Mitchell Trubisky.

“He runs really good routes, he’s got good ball skills, he gets open and he’s fast -- so we could use his speed to open up things in the offense,” Trubisky said.

Wheaton averaged 17.0 yards per catch for Pittsburgh in 2015.

“We’ve got to make sure we’re doing a good job putting him in positions and routes he’s good at,” Loggains said. “There is a timing element with the quarterback that has to be worked on and it’s hard to do that until you’re healthy and ready to go, so we’re going to live through a little bit of growing pains with those two guys. But we’re excited about them because they’re both veteran guys and they should be able to get in there and help, and as they get more exposures we’ll get more exposures on them as well and Mitchell will start to feel more comfortable with them that way.”