Celtic turn their attention to Spurs flop Bent and Russia star Pavluchenko

Manager Strachan admitted last week that Swiss international Alexander Frei was on his radar, but Sportsmail understands he is joined by Roman Pavluchenko of Spartak Moscow and Tottenham Hotspur's Darren Bent as leading options under active consideration by the SPL champions.

Target man: Roman Pavluchenko (right) would give Celtic a physical presence in attack

The Parkhead club have pulled out of the Old Firm race to land Kyle Lafferty, with Rangers now firm favourites to sign Burnley's young Northern Ireland international.

Celtic set a deadline on the package of £2.75million plus Derek Riordan and a friendly match at Turf Moor they offered last week and are now looking elsewhere to bolster their forward line.

Strachan has been a long- term admirer of Frei, currently with Borussia Dortmund and recuperating from the knee injury that cut short his involvement in Euro 2008.

He is expected to be fit within six weeks, but it is the interest in Pavluchenko and Bent which will most intrigue Parkhead supporters.

Towering Russian Pavluchenko scored in both legs against Celtic as Spartak crashed out of last season's Champions League qualifiers on penalties at Parkhead.

The 26-year-old has been a prolific scorer for his club since joining in 2003 and netted a Euro 2008 goal against Spain last week.

Striking pair: Bent (above left) and Frei, pictured on the sidelines for the Swiss, are being considered by Celtic boss Gordon Strachan

His situation is now being studied by Parkhead chief executive Peter Lawwell, who is also closely monitoring Bent's position.

The 24-year-old cost Spurs a club-record £16.5m when he moved from Charlton Athletic 12 months ago, but it is understood that the England internationalist does not figure in the future plans of White Hart Lane coach Juande Ramos.

The Barclays Premier League club are willing to move him on and could also consider a loan deal that would enable Celtic to offer him the chance to recapture his previous form north of the border.

Lawwell remains in negotiations to extend and improve Scott McDonald's contract after his prolific debut campaign, but Celtic remain determined to add high-level options to their strike force before embarking on a new Champions League campaign next season.

With McDonald due back in Scotland today, it now seems certain the 24-year-old will commit to the improved contract that will tie him to Celtic until 2012.

His agent, Lou Sticca, said last night: "I met with Peter Lawwell about a month ago to discuss Scott's performances in the first 12 months of his Celtic career.

"Peter indicated that the club were very pleased with Scott to date and, as such, would like to offer him a new contract. Talks over the contract have been ongoing since."