Michael Owen has real doubts over Manchester City's Champions League winning credentials.The former England striker was speaking on BT Sport after City's 2-1 defeat to Shakhtar Donetsk - their first of the season.City put out a rotated side against the Ukranian's meaning not too much could be taken from the result, but it didn't stop Owen from voicing concerns over Pep Guardiola's side.The Manchester club have dominated English football this season, topping their Champions League group with a game to spare while also opening up an eight-point lead in the Premier League after just 15 games.That lead has come on the back of a record-equalling 13-game winning streak, tantalisingly setting up a potential new record when City take on local rivals, and second-place, Manchester United.They have been the story of the season as Guardiola finally looks like achieving his goal of building the team that he wants, encouraging flowing attacking football that has made fans of all clubs (except United, naturally) stand up and applaud.The praise has extended into Europe, too, with City being heralded as arguably the finest team in all of Europe - and moving them into position as favourites for the Champions League.Michael Owen, however, believes the brakes should be on such praise and that Man City still have something to prove in Europe.“Is there a better team in Europe right now? Probably not to be honest. Man City are absolutely flying,” said Owen.“At the moment you would have to say City are our strongest team but I think the biggest question with them is – is their style of play conducive to knockout football against the big teams?“I think they might be a bit too expansive and open against the big boys – but obviously we are going to find out.”It does remain the one big question hanging over Man City - just how will such an attacking team handle the best offensive outfits in the world? Can that defence handle the likes of Barcelona, PSG, or Real Madrid?

Their results against a high-flying Napoli went some way to answering the question, but it still remains to be proven.

Still, Owen remains enthusiastic about English sides in Europe this season.

“When you look at the English clubs, I just think that we have got great representation this season,” he said.

“With all due respect to the teams that were in last season, Leicester obviously got the furthest which was an amazing achievement, but there were teams in there out of form or weren’t really our best teams.

“This year we have literally got our five best teams all in good form and this year surely we will be having lots of teams back in the latter stages like it used to be.”