Martin O’Neill has conceded Celtic cannot afford to slip up in Sunday’s crucial top-of-the-table clash with Hearts at Tynecastle.
The Jambos currently hold a six-point advantage over both the Hoops and Rangers in the battle for the William Hill Premiership crown.
A loss in the capital would see O’Neill’s men staring at a nine-point gap as they look to defend their title.
“It’s going to be very big, no question about it,” O’Neill said on Friday. “If we get beaten, it’s a long way back for us. It is a bit of a trek at the minute, so we would go out to try and win the game if we can.
“It’s not the end of the road (if Hearts win) but nine points would be a lot to claw back with 15 games left.”
Celtic have already been beaten twice by Hearts this season — first under Brendan Rodgers and then Wilfried Nancy — but O’Neill brushed aside any suggestion his side, fresh from a 2-2 Europa League draw away to Bologna on Thursday, would settle for a draw.
“I don’t think that’s in their nature,” he said. “If you look at last night, the way we started the game, we closed the players down, we scored a goal from closing players down.
So we went to take the game to Bologna. What’s the point in sitting back? Obviously, as the game goes on, we get a man sent off and second half, we had to retreat.
“They drove us back, as you would expect. But for us, we will be as positive as we possibly can, and we’ll try and win. If we can’t win it, we’ll try and save it.”
O’Neill also confirmed striker Johnny Kenny is a concern for Sunday after suffering a calf issue during his substitute appearance against Bologna.
“I think he’s gone for some sort of scans this afternoon, but we’ll see,” said O’Neill. “He might be a doubt, I’m not sure. He just said he felt it during the course of the time he was on. Hopefully other than that, we’re ready to go.”
Any absence for Kenny could be balanced by the arrival of Czech forward Tomas Cvancara, who completed a loan move from Borussia Monchengladbach earlier this week, along with the potential return of Kelechi Iheanacho from injury.
Cvancara has not featured since turning out for Turkish side Antalyaspor during a loan spell on 24 November, but the striker says he feels fully prepared for a possible debut in Sunday’s high-pressure visit to the league leaders.
“Yeah, I had preparation in Germany, basically full January, so for me it’s no problem to jump in,” the forward said on Friday. “So I would say that I’m ready.
“I trust myself, I trust the team, I trust my qualities and I’m not afraid to step in, so if the manager needs me, I’m there.”