Chicago Bears receiver Alshon Jeffery suffered a strained calf muscle during a recent training camp practice, which forced him to miss Thursday night's pre-season game.
Coach John Fox chose not to reveal the problem earlier, with the Bears holding a closed walkthrough on Wednesday before the first pre-season outing.
"He did it in a practice before we came [back to Chicago]. He'll be day to day," Fox told reporters.
"He'll be back in Bourbonnais because he has to get treatment," Fox said. "But I can't [say when he'll back on the practice field]. I'll keep you posted."
Jeffery was seen on crutches and wearing a walking boot on Thursday, which will be seen as a significant blow for the Bears after he caught 85 passes for 1,133 yards and 10 touchdowns last season.
