SUNDERLAND defender Michael Gray's move to Celtic rests on whether or not winger Steve Guppy is sold in this month's transfer window.

Guppy is surplus to requirements at Parkhead and he has attracted the interest of a number of clubs south of the border, with Wigan Athletic leading the chase.

And Northern Echo SPORT understands that Celtic boss Martin O'Neill has told Gray that the left-back will only return for a second stint with the Bhoys if they can offload both Bobby Petta and Guppy from the wage bill.

Petta has since joined Premiership side Fulham, while interest remains quite high on Guppy.

But if a deal fails to materialise for the former Newcastle United winger then Gray will have to face up to life at Sunderland again, where he knows his future is bleak.

Meanwhile, Gary Breen should be back in contention for a place in the Sunderland starting line-up next weekend, but manager Mick McCarthy admits he could have trouble reclaiming his place.

Breen has not played since mid-November after suffering knee ligament damage.

And, after coming through an initial shaky spell without the Irish defender, transfer-listed pair Phil Babb and Joachim Bjorklund have kept four consecutive clean sheets during a run of five successive victories.

That form has helped Babb, who signed on a free transfer in the summer of 2002, overcome many of his critics in the Stadium of Light stands and McCarthy has been amazed by the former Liverpool man's displays.

"Babb has been excellent but so has Jocky Bjorklund," said McCarthy. "I can't say why it went so pear-shaped for them last year.

"All I can say is that they came in when this club was in a difficult position. They were big earners at that time and perhaps there was resentment for that reason.

"But if people said they didn't do anything to warrant that pay then, then they have certainly contributed since.

"Babb has played five on the spin now and we have won all five, what does that say? And Jocky has been terrific for a number of games now."

McCarthy, whose side beat Forest with a solo strike from Julio Arca, is still amazed by the way referee Martin Atkinson ruled out an earlier effort which found the net.

Just before the quarter of an hour mark, Stephen Wright ran away to celebrate his second goal of the season after claiming he touched Arca's indirect free-kick.

But the linesman told Mr Atkinson that the right-back never got his head to the ball, but McCarthy said: "Wrighty said he touched it and it was a strange celebration if he didn't. I find it strange that the assistant got a better view of the incident than the referee. How is that?

Read more about Sunderland here.