Claudio Ranieri was painted as a clown for his juggling of Chelsea's attacking resources a fortnight ago. By introducing a third striker when Monaco went down to 10 men, the Italian played his part in the 3-1 defeat. At Stamford Bridge tonight there can be no such mistakes. The head coach has to get his selection right up front.

With Chelsea needing to score at least twice to reach the Champions League final, there is as little margin for error at the head of the team as at the back, where slips could allow Monaco to kill off the tie.

Fifty-six matches into Chelsea's season, nobody can be sure Ranieri knows his best combination. Consistency of selection in attack has hardly been a feature and none of his strikers has set Europe alight. Chelsea's leading scorer in the Champions League's group and knockout stages has been the midfielder Frank Lampard.

His three goals put him ahead of Hernan Crespo, Eidur Gudjohnsen and Wayne Bridge on two each. Jimmy Floyd Hasselbaink and Adrian Mutu have each scored once. With Mutu ruled out because of injury, the options available to Ranieri in attack have been slimmed down. In theory it leaves him with three choices: Crespo and Gudjohnsen, Hasselbaink and Gudjohnsen or Hasselbaink and Crespo. The last of those can probably be discounted: they have scarcely started together and the combination offers Chelsea little variety.

"Claudio might well see them as both the sort of strikers who like to be on the end of things," says Kerry Dixon, the former Chelsea striker who is a regular commentator with the club's radio station. "Neither of them likes to drop off, receive the ball to feet and bring others into play in the way Eidur and Mutu do."

Gudjohnsen has been almost a fixture in Europe since the competition's winter break, missing out only at home to Stuttgart when Crespo played alone up front. The Icelander will be required anyway for his ability to create. With Damien Duff injured, Chelsea need a touch of the unexpected from more than Joe Cole.

The question is whether he should be partnered by Crespo or Hasselbaink. Crespo is the obvious choice. He scored nine goals in 12 Champions League games for Internazionale last season and equalised at Monaco last month. He also found the net at Lazio in November.

Hasselbaink, the club's leading scorer, has been little used by Ranieri from the start in Europe, beginning only two games since the qualifier. But he has been strongly stating the case: "If I do not play then it will be very hard on me. The most important thing is that we need to score goals and I have shown this season that is what I do best. I am not criticising my team-mates but I am just talking facts. My goals are like a business card. I believe that this game could be my match of the season."

Hasselbaink would offer more pace but a little less finesse than Crespo. Dixon feels the Dutchman's understanding with Gudjohnsen makes him the better bet. "They combine better than any other pair and that might get them the nod," he says.

"Of late Eidur's probably been turning in some of his better performances and getting back to his best. Jimmy is still the top scorer and is heading towards the 20 mark again. For me he's the best goalscorer at the club. I would say as a pair they probably offer the most threat."