JT will be rested for tomorrow's Premier League game with Wigan but Di Matteo admits he cannot afford to leave him out for too long.
He said: "With a rib injury, it needs time to heal. Every time you get a knock, you probably go a step back.
"We're just trying to manage the injury at the moment and we'll just have to see how quickly he can recover.
"It's one of those injuries that are difficult to deal with because there's not much you can do. It's in a position where it's difficult to make it better.
"We need to just deal with the pain level and give him a bit of time to recover."