The young Republic of Ireland international, who burst onto the scene with a debut goal at Hearts last season, has provided vital goals for John Hartson the last two weekends.

He has been so impressive he has kept World Cup winner Juninho on the bench and looks set to do so again as Celtic chase the victory which would seal a UEFA Cup place tonight.

O’Neill admitted McGeady has exceeded expectations, saying: “He is doing wonderfully well and it’s going to be a big game for him.

“He is making things happen for us. His run for the second goal against Dundee was fantastic and he delivered the ball for Hartson’s winner on Saturday.

“Those contributions will stand him in really good stead. He is full of confidence and you don’t knock that out of him.

“We have to keep encouraging him. I’m really pleased with his progress. I guessed he would do well for us and some of his play is beyond expectation.”

Celtic need to match Shakhtar Donetsk’s result to book their involvement in Europe beyond Christmas.

The eastern Europeans face Barcelona in the Ukraine but O’Neill fears Frank Rijkaard’s men are so confident of beating any one in the Champions League they will not mind finishing Group F in second place behind AC Milan.

He said: “The way Barcelona are playing they wouldn’t be overly concerned whether they would finish first or second in the group. If they don’t send their strongest side you won’t get a chirp out of me.

“They have earned the right to play any team they want. They have got those points on the board and it’s wonderful to be in that position.

“I have to work on the assumption that Milan will go full steam ahead here. That would be the top of my thinking.”

Hartson is vital to Celtic tonight having brushed off the threat of Hibernian with his double at the weekend.

Team-mate Chris Sutton said: “At the start of the season he was coming back from an operation but when he is fit he has proved what a player he can be for Celtic.

“He won the game for us on Saturday and he will be important for us tonight.”