CELTIC top scorer Scott McDonald today refused to be bitter about being left on the bench for all but 13 minutes of the 1-0 defeat in Barcelona.

Manager Gordon Strachan's line-up stunned the thousands of Hoops fans in the Nou Camp last night, and those watching the game back home.

Jan Vennegoor of Hesselink was left to forage alone up front - even though the Parkhead side needed two goals to get through - and Shunsuke Nakamura was the surprise choice to try and get forward to support the giant Dutchman.

It was not the first time McDonald has been left out on a big European night. Chris Killen got the nod to play the lone striker role in Lisbon against Benfica in the group stage as the manager revealed he need to protect McDonald with upcoming league games in.

Coincidentally, Celtic went down 1-0 that night, too. But McDonald - who is reportedly a £6million summer signing target for Newcastle - has no intention of moaning at anything but the result in the Nou Camp.

And he said of the decision to leave him out: "It is always disappointing, but you can understand the manager's decision.

"It was tactical and he felt it was best for the team. As I said, I am disappointed, but I was fully behind the boys and it was just great to get on at some stage."

By the time McDonald did come off the bench, to partner Georgios Samaras as a replacement for Paul Hartley for the final 13 minutes of the match, any real hopes that Celtic could turn the tie around had long since receded.

They would have required three goals to knock out Barca thanks to Xavi's goal in the opening two minutes which gave the Catalans a 4-2 aggregate lead.

McDonald admitted watching from the sidelines as that early goal sailed past Artur Boruc was hard to take.

He said: "It was disappointing to lose a goal like we did in the first minutes.

"But I thought we came back into the game, especially in the second half. We played some nice football at times and created a couple of chances.

"But Barcelona are an excellent side, and I fully expect them to maybe win the Champions League this year."

Asked what he can take from the experience, he said: "Everything. Win, lose, or draw, it has been fantastic. We have achieved a lot and I think I have become a better player for it."