Cammy arrived back in Edinburgh from Australia this morning as Glasgow prepare for their clash with Ulster for a place in the final on 20 December.
"Cameron has been on the phone already and will join us for the team meeting this afternoon. If he is fit he will play on Friday," Hugh Campbell, Glasgow's coach, said this morning.
"Before he left on his late World Cup call-up he had been very involved with us, and he feels a vital part of the team that has got us to the Celtic Cup semi-finals. He made his intentions quite clear that he was anxious to play in this game.
"We are predominantly a young side and need someone of Cameron's experience and leadership. We know we will have to be at the top of our game because Ulster represent a huge challenge. They are going really well in the Celtic League and are one of the most consistent sides around.
"But this is also a real opportunity for us to get back on track, and we are looking forward to the game.
"We have the bonus of playing at home, and the players know they have something to prove after their performance at Ravenhill."
Mather's return would be a huge boost to Glasgow, whose chief executive, David Jordan, is expecting a bumper Friday night crowd. "It looks as if it will be close to a 5,500 sell out," he said. "Ulster have taken 800 tickets. So we are certainly looking for a big crowd and a great atmosphere.
"We lost 17-20 at home to Ulster in last season's Celtic League quarter-finals, and I am sure they are looking at this semi-final and saying 'game on.' It should be a great match.”
In the event of a tied Celtic Cup semi-final there will be 10 minutes of extra time (five minutes each way) with the first team to score the winners. If still tied, the winner will be decided by the team with the most tries in the match, then the fewest red cards in the match, the fewest yellow cards in the match, or, as a last resort, the toss of a coin.