ON one hand Steve Bruce did not want to detract from a Sunderland performance that offered an insight into the progress that has been made in the last four months. On the other the memorable victory over Liverpool looks to have arrived at a huge cost.

While striker Kenwyne Jones, who headed to hospital to check on an ankle complaint, and full-back George McCartney, replaced at half-time with illness, should not take too much time to recover, there are major concerns over the fitness of Lee Cattermole.

The dynamic midfielder, who once again highlighted his worth to the Sunderland midfield by closing down almost every Liverpool move through the middle, will have his knee further assessed within the next 24 hours amid fears that he has damaged medial ligaments.

While that would not be as bad as if he had ruptured his cruciate ligament, there are still concerns Sunderland will be without the £6m Under-21 international for the remainder of the year.

“The worst case is that it’s months rather than weeks,”

said Bruce, who handed Bolo Zenden his debut in the middle after the departure of Cattermole just before the hour mark.

“That’s the big downside because we can’t do without our big players just yet.

“Thank God we’ve signed Zenden because we are short.

Kenwyne twisted his ankle and Catts twisted his knee.

“We hope it’s not his cruciate because that would be a killer. When he comes off you know there’s something wrong.”

The injury to Cattermole has come at a frustrating time for Bruce, who is acutely aware of the partnership in the middle of midfield that has been growing in promise between the 21-year-old and Lorik Cana.

Cana, handed the captaincy by Bruce, was a surprise recruit when Sunderland paid £5m to Marseille for him but the Albanian international delivered a display against Liverpool worthy of earning long-term respect from fans already worshipping him on Wearside.

For the first half the 24- year-old ran the midfield alongside Cattermole before turning in a majestic central defensive performance.

“I couldn’t believe Marseille made him available because of what he was in that part of the world, he was a cult hero there,” said Bruce.

“It was possibly the easiest transfer we made as well. I couldn’t believe how easy it was.

“We agreed the fee in 24 hours, he came and flew to Amsterdam and signed that night.

“He didn’t want time to think about it or go around the stadium or hear about what we were trying to do. He just wanted to come and play in England.

“I went down the line that people in England will love the way you’ll play. He was immense on Saturday.

“His second half performance was arguably, individually, as good as I’ve seen in a top, top game and I’ve seen some good ones.

“I knew Lorik would turn out to be a cult figure here and he’s proven to be that.”

While there is growing excitement following Sunderland’s victory over Liverpool, just a fortnight after being within seconds of winning at Manchester United, Bruce is urging caution.

“We have to keep people’s feet on the ground now and that’s what we’ll do all week,”

said Bruce.

“It’s okay showing up against Manchester United and it’s okay showing up against Liverpool, and be confident, but we’ve got to make sure we do the same when we go away from home week in week out, starting at Birmingham next Saturday.

“We’ve got six months ahead of us. We’ve set certain standards.

“We’ll assess the whole thing in six months, whether we’re a good team and what improvements we’ve made, but the signs at the moment are looking very decent.”