The Derby County left-back picked up the knock in Tuesday's 1-1 draw with Cardiff City, which forced him to be replaced just before the half-hour mark.
Rams boss Nigel Clough says the 34-year-old will have his fitness assessed closely ahead of the weekend trip to the King Power Stadium.
"Gareth's calf tightened up so we made sure we got him off pretty quickly," Clough told the club's website.
"We're hopeful hasn't pulled or strained it as he's had something similar to this situation before.
"He'll get some time with the medical team in the next few days to hopefully ease things down a little in his calf and get him in contention for Saturday's game, all being well."
Former Welsh international Roberts has made 17 appearances for Derby this season.