Celtic look likely to lose Artur Boruc, their goalkeeper, for at least a month after tomorrow night’s Champions League clash with AC Milan in the San Siro, if tests show that the Pole needs to go under the knife for a knee operation.

Boruc, slightly to the chagrin of Gordon Strachan, the manager, has been making indiscreet noises for some weeks now that he needs to have “a knee problem” cleared up. Celtic have chosen to wait until their Champions League group-stage programme was finished before assenting to Boruc’s wishes, but now he looks likely to get his way. “Artur will have tests after the Milan game and then we’ll take things from there,” Strachan said yesterday in the Italian city.

It remains uncertain how long Boruc will be out for, but, if the operation is merely a cleaning-up exercise, Celtic will hope to have their talismanic goalkeeper back in time to face Rangers at Celtic Park on January 2.

Meanwhile, Paul Hartley may or may not be a student of the philosophy of Gary Player, the golfer, but the Celtic midfield player yesterday quoted from the canon of the great South African as he surveyed the San Siro showdown.

Celtic need a point to guarantee their progress to the last 16 of the tournament, and Hartley, among other aspects, claimed that Celtic would have to “get lucky” if they are to halt Carlo Ancelotti’s European club champions.

Asked what it would require on the night, Hartley said: “Sometimes you have to ride your luck, sometimes you have to take your chances when they come along. So we’ll need a bit of both. We’ll have to be at our very best on Tuesday, we’ll have to have our team performing at its maximum.”

Hartley, who is expected to play alongside Massimo Donati and Scott Brown tomorrow, insisted that Strachan’s side will enter the arena trying to win the match, rather than attempting to hold out for a draw.

”I don’t think our approach will ever change, no matter where we go,” he said. “We go to places and try to attack and try to win – that’s just the way we are. So, hopefully, when we’ve got the ball in Milan, we can be brave with it, and make things happen. We’ll go there and be very positive and try to win the game.

“Maybe we won’t need to score. Maybe it will be 0-0. But we know we’ve got players who can put the ball in the back of the net – Scott McDonald, Jan Vennegoor of Hesselink, Aiden McGeady. We might go there and be under a lot of presure on Tuesday for long periods, but I’m sure we can handle that.”

Celtic will need a draw, unless Benfica can hold Shakhtar Donetsk to a draw in Ukraine, in which case Celtic would go through as the second-placed team in the group.

“We’re going into it with a lot of confidence after the Donetsk game,” Hartley said. “We know it will be a very difficult game in Milan, and everyone keeps harping on about our away record, so hopefully we can turn the tables and get something.”