BRENDAN Rodgers last night admitted Celtic will have to perform far better against Zenit St Petersburg in their Europa League last 32 ties to prevail than they did in their William Hill Scottish Cup win over Partick Thistle yesterday.

Rodgers’ side progressed to the quarter-finals with a 3-2 victory over Alan Archibald’s team courtesy of a hat-trick from James Forrest, the first of his professional career, at Parkhead.

But the Scottish champions endured a far more difficult afternoon than they needed to after gifting first Kris Doolan and then substitute Conor Sammon goals and their manager knows they must tighten up at the back against Zenit

“We clearly need to play better that what we did today,” he said. “But hopefully the occasion brings that performance level up.

“They are two really exciting games for us. We have the first leg here on Thursday and that should be a fantastic game. We will get ready for that. We will prepare over the course of the next few days and then we will look forward to that on Thursday.

“Staying in Europe past Christmas was the aim right from the beginning of the season, that was the next step for this group. So it’s great to be qualified for this phase.

“Now we want to try and maximise where we can go in this competition. We recognise there are some crack teams who are probably disappointed they aren’t competing in the latter end of the Champions League, but for us the experience will be great. We will see what we can do over the two legs.”

Rodgers is hopeful Mikael Lustig, the experienced Swedish right-back who made his comeback after a fortnight out yesterday, will be available for selection against Zenit despite requiring medical attention for a knee injury before half time yesterday.

“It looked and sounded horrible,” he said. “He had a reaction when he went down. He had a real bad stud mark on his knee. But he was able to continue on so hopefully he’ll be fine.”

Rodgers also admitted that Tom Rogic, the Australian attacking midfielder who has been sidelined for over two months with a knee injury, could feature against Roberto Mancini's men even though he was prevented from coming on yesterday when Sammon netted.

Rogic was set to replace Forrest near the end of the match, but Rodgers put on Eboue Kouassi after the visitors netted.

“I had to apologise to him for that,” he said. “At 3-1, we should have been comfortable in the game. But of course when the late goal goes in it changes your thought process. So unfortunately for him he is going to have to wait. But he is back in training and he looks great.

“Tom is going to get some minutes with the under-23 squad on Monday. He has been out for 10 weeks now and needs some game time. He is working pretty hard in training, but he needs some game time. If he gets that it will give him confidence if he needs to play.”