The defender feared he had suffered a season-ending injury when his right leg crumpled awkwardly underneath Luis Suarez during the 1-1 draw with Liverpool at Stamford Bridge last Sunday.
A scan, however, showed the 31-year-old had suffered only minor damage to his knee and Di Matteo expects the influential defender to return in time for the trip to Sunderland on December 8.
"With JT, we're looking at approximately three weeks," said the Italian. "Fortunately, it's not as bad as we first thought. It's an MCL [medial cruciate ligament] strain."
He added: "Frank Lampard won't be featuring at West Brom but he's not far off, we want to make sure he's 100 per cent and not take risks."