DERK Boerrigter has admitted Celtic must be far more ruthless in their finishing if they are to have any hope of surviving in their formidable Champions League group.

The Dutch winger was a substitute as Celtic went down 2-0 to two late AC Milan goals at San Siro after they had failed to convert a number of chances. It had been "an unnecessary defeat" he said. They now face group leaders Barcelona in Glasgow on October 1 before the double-header against Ajax at home on October 22 and in Amsterdam on November 6.

Boerrigter played all six of Ajax's Champions League games against Real Madrid, Borussia Dortmund and Manchester City last term and scored in the Bernabeu. He said Celtic's inability to take chances was far more important than the fact they had plenty of possession in what was generally an encouraging display in Milan. Uefa's statistics showed Celtic had 50% possession in the first half and 46% over the 90 minutes.

"In this group you have to kill," the 26-year-old said. "We can take the positives but the most important thing is points. I would rather play badly and win than play well and lose. You have to try to make every shot go in because if you don't teams can hurt you. It was disappointing and an unnecessary defeat. We had a lot of possession but that doesn't mean anything when you don't score."

Lennon was bold enough to add Teemu Pukki and Boerrigter to the attack in the last 15 minutes when the game was still goalless, with Anthony Stokes the only recognised striker to start. It was the Irishman's first appearance in the group stages and he hit the bar with a free-kick amid a reasonable performance. Now he has backed himself to continue leading the attack against Barcelona.

"It wasn't guaranteed I would start but I thought I did reasonably well in a tough role," said Stokes, who has often been left out of major fixtures. "On your own it's never easy but I got great support from Kris [Commons], Sammy [Georgios Samaras] and Adam [Matthews] - who I thought was outstanding - and, as a team going forward, I thought we did well."