Celtic defender Glenn Loovens says opponents Dinamo Moscow will hold the advantage when the sides meet in the Champions League qualifiers.
The Russians are well into their domestic season, while Celtic are playing friendlies ahead of the first leg at Celtic Park on 28 July.
"They have already played about 13 games, so they have played a quarter of the season already," said Loovens.
"So they have an advantage, but that shouldn't be an excuse for us."
Celtic will look to take a lead to Moscow for the return leg on 4 August.
But Dutch defender Loovens says it is vital the players sharpen up ahead of the double header against Dinamo.
Celtic face Cardiff away on Wednesday before taking part in the Wembley Cup against Egyptian outfit Al Ahly two days later and Tottenham on 26 July.
Loovens said he was confident Celtic would be firing on all cylinders in time for the Champions League qualifiers.
"We have only played one game and we know that, in a week's time, there is an important game coming up," he said.
"So we just want to get started, get the friendly games out of the way and go for the ones that really count.
"I don't really watch Russian football to be fair - but you know that it will be tough no matter who you draw and Dinamo Moscow will be tough opponents."
Loovens revealed he was enjoying life under new manager Tony Mowbray as the club look to wrest the Scottish Premier League title back from Rangers.
"If there is a new manager,it is always going to bring an atmosphere to the club because everyone wants to prove themselves over and over again," the former Cardiff defender said.
"Maybe it's a bit too soon to say, but he loves possession football. We practise that every training session and it's great to be involved with it.
"We also train a lot with the ball. So, from our point of view, it's been a good pre-season.
"He looks for a lot of movement and change up front, so I think it will be good to watch."