Roberts will be unavailable until March 1 after receiving a three-match ban for his red card against Hull on Tuesday night.
The 35-year-old was sent off in the closing stages of the 2-1 defeat at the KC Stadium for a lunging tackle on Tigers forward Nick Proschwitz.
Boss Nigel Clough, whose defensive options are stretched with James O'Connor, Mark O'Brien and long-term absentee Shaun Barker all out with knee injuries, confirmed he has enquired about the availability of a left-back on loan, but insists he will solve the problem from within his existing squad if his search to bring in a new player is unsuccessful.
"We are looking at bringing someone in on loan and we've made an enquiry about one player, but if we can't do something there we'll look to solve the problem from within," Clough told the club's official website.
"We've done that for the majority of the season and we've set our stall out this year to give people a chance from the group we have.
"But Gareth's position is more of a specialist one and that's why we're looking at bringing in a left-back on loan with a bit of experience.
"If it doesn't happen, though, we'll go with what we've got and go from there."