UEFA CUP/Preview: Celtic's Stilian Petrov is winning his fitness battle to face Celta Vigo in the UEFA Cup third-round clash at Parkhead tonight.

The Bulgarian international's hopes of facing the Spanish side have been hanging in the balance since having 15 stitches in a facial wound at Livingston on Sunday.

But yesterday the news from Parkhead was more encouraging and manager Martin O'Neill is more hopeful that the influential midfielder will be in his starting XI.

"Stilian trained this morning and he is feeling better by the day," he said yesterday evening. "He is still pretty sore looking, but he is up for it and he wants to play. Tomorrow is another day and it gives him a better chance. He's just beginning to eat now and I was so pleased to see him this morning.

"He is raring to go and another day will help. I am more hopeful thaI was two days ago and he is feeling no ill effects. It looks pretty sore, but he feels better and I will give him every opportunity to play."

Petrov's determination to play is a huge relief for O'Neill, who looks set to be without Alan Thompson for the first leg. The former Aston Villa midfielder suffered a thigh strain in the weekend win at Livingston and having missed training yesterday he is rated extremely doubtful.

The Celtic manager's biggest decision is whether to bring John Hartson back into attack and move Chris Sutton into midfield.

The Welshman is on song at the moment and Sutton's role in the middle - with Paul Lambert missing out - at Ewood Park was crucial in beating Blackburn in the last round.

The Northern Irishman admitted that derogatory remarks from Blackburn before that second leg gave his side enough motivation to last six matches.

But O'Neill now feels under no extra pressure despite the fact that Celtic have failed to beat Spanish opposition after seven opportunities and that the club have not been in Europe past Christmas in 23 years.

He admits that his players are flying high after their victory over Graeme Souness' men and he acknowledge that a clean sheet tonight would help his side end that hoodoo.

"We are now back to the old European format of away goals and they have a big bearing on the proceedings," O'Neill said. "A goalless draw wouldn't be a disaster because we are capable of scoring there. Spanish teams are difficult to dislodge and generally they are half-decent teams.

"But the players are buoyed by the win against Blackburn and if we go through then I would be delighted."