The 22-year-old midfielder has not played since the 2-0 home defeat by Blackpool on 28th December because of a back problem which required complete rest.
Bruce said: "He's training and we hope by the middle of this week that he's joining in."
Specialists warned Cattermole that the injury could develop into a stress fracture if he did not sit out and, having already seen his captain miss a significant proportion of his time on Wearside because of fitness concerns, Bruce acted on that advice.
physically working
However, the £6m signing from Wigan Athletic has now resumed light training and is expected to step up his work over the next few days to hand his manager a boost in the face of continuing injury problems.
Bruce continued: "He's out there training and physically working - but he has been out 10 weeks as well now.
"It doesn't get any better, week in, week out, to be honest."
As Cattermole prepared to return to full training, keeper Craig Gordon was heading for Sweden to consult a specialist over his knee injury.
The 28-year-old Scotland international was an unused substitute for Saturday's 0-0 Barclays Premier League draw at Arsenal, the second successive match for which he has provided the back-up to Belgian Simon Mignolet.
However, Bruce revealed on Thursday that Gordon would be in Scandinavia on Monday to try to get to the bottom of the problem which forced him to return early from international duty last month.
