AC Milan captain Paolo Maldini has warned Celtic they will face an even more formidable team at the San Siro next month.
Both teams battled out a goalless draw in the first leg of the last 16 of the Champions League at Celtic Park last night.
The Scottish champions had hoped for a home win ahead of the return leg in Italy in a fortnight's time.
Instead, the clash ended in stalemate with Celtic now facing a battle to remain in the competition and become the first Scottish club to qualify for the last eight.
And Maldini - who made his 100th Champions League appearance last night - reminded Gordon Strachan's men they will be up against even stiffer opposition next time around.
Ronaldo may be cup-tied but Clarence Seedorf and Filippo Inzaghi should be back from injury, along with Marco Borriello who was banned for the trip to Glasgow.
'We had some problems with the strikers but hopefully we will have some players coming back for the return,' said Maldini. 'We will be better and, of course, we are confident we can win the tie.'
Jan Vennegoor of Hesselink came through an injury scare to partner Kenny Miller up front but neither player converted the chances they created.
Celtic's other main threat was Shunsuke Nakamura but his famous free-kicks failed to break down a stubborn Milan defence, led by Maldini.
The veteran defender, 38, reckons goalkeeper Zeljko Kalac had a reasonably quiet night and he predicts a far busier shift for Celtic's Artur Boruc in the return leg.
He said: 'It was a tough game and we knew that it would be a tough game. We deserved the draw and now we will have more chances at home.
'We didn't suffer too much and the strikers didn't give our goalkeeper too many saves to make.'
Coach Carlo Ancelotti was also confident the six-time European Cup winners would progress to the last eight.
He said: 'We have more of a chance after this game and I am confident we can go through. Celtic can score over there but we can always score two.
'I was happy with the performance of my side, we tried everything in attack and that is what I wanted. We didn't allow Celtic to play the way they wanted to play.
'They didn't cause us any problems, they were only dangerous from free-kicks and corners.'