Glasgow: Kevin De Bruyne is out of Manchester City's Champions League trip to face Celtic in Glasgow, his manager Pep Guardiola confirmed on the eve of the game.
"Kevin is not a big injury -- in two and a half or three weeks, maybe he will be ready," Guardiola said at Celtic Park on Tuesday.
The Belgian playmaker suffered a hamstring injury towards the end of City's 3-1 win at Swansea City in the Premier League on Saturday that maintained their perfect start to the season.
If De Bruyne is out for three weeks, it would mean a return after the October international break in time for City's next Champions League game away in Barcelona.
City will also be without Fabian Delph and Vincent Kompany for the Group C showdown as they look to build on a 4-0 victory over Borussia Moenchengladbach last time out.
Celtic opened their campaign by suffering their record European defeat, going down 7-0 in Barcelona.
Given City's form, many will fear the worst for the Scottish champions but Guardiola knows the unique Parkhead atmosphere could act as something of a leveller.
"Everyone talks to me about the atmosphere, I'm looking forward to playing here. I know how strong they are here," said Guardiola as he prepares to sample playing in Glasgow's East End for the first time.
"We've started well and tomorrow we have a big opportunity to step forward. This group is so tough. I'm so happy with the performance against Gladbach but it is just one game."
A win for City will see them equal Tottenham Hotspur's 56-year-old English record of 11 wins from the start of the season, but Guardiola insisted that was not on his mind.
"Tomorrow I am not concerned or focused on a little, little record.
"In the future an English team will win 12-13 games in a row, that is going to happen. What I want tomorrow is to play well."
For their part, Celtic are coming off a 6-1 win against Kilmarnock at the weekend and their record at home this season shows eight wins from eight games with 32 goals scored.
Their manager Brendan Rodgers knows, however, that City are in a different class entirely to all previous visitors this season.
"It is really exciting," said Rodgers. "But Man City are a top team, everyone can see that clearly, they have that world-class ability, great individuals who are working hard."
"We know we have to bring our A game to have any chance and that is something hopefully we can do. The reality is if they bring their A game and we bring ours, they win."
"But we know we have to make it as uncomfortable as we can for them. As a coach and players these are the types of occasions and games that you look forward to and we look forward to it."
Rodgers also confirmed that Craig Gordon will start in goal in place of Dorus de Vries as the Dutchman is still not 100 per cent after having to go off at half-time in the win over Killie.