Have Chelsea all but wrapped up the title already?

Are Chelsea a one man team?

Chelsea have started the new season in superb and, so far, unbeaten form, but they've not won anything just yet.

Some pundits have already started talking like the Blues have the Premier League title sewn up, but Sunderland showed at the weekend just how to stifle Jose Mourinho's side, in particular doing a real job on star striker Diego Costa.

Costa was fortunate to escape a red card against the Black Cats and was clearly frustrated, leaving the Blues without the spearhead who had proved such a potent force in the opening weeks of the campaign.

The Spain international started his Stamford Bridge career with seven goals in four Premier League games, but he was been less prolific recently, with two in his last four league games and two in his last six outing in all competitions.

Stifle him and Chelsea do not have too many other options in attack, with Loic Remy a peripheral figure and Didier Drogba well past his imperious best.

Bet 10 Get 30 with Betfair Plus Money Back if you Lose

Of course there is a lot more to Chelsea than Costa, but he is the figurehead and if other coaches catch on to the way Gus Poyet set his Black Cats side up on Saturday, the Blues may find things get tougher as the season progresses.

And it is not all about Chelsea, their dominance so far has also been a product of the likes of Manchester United and Liverpool failing to fire.

The Anfield outfit look all but out of the title race already, having come so close to glory last season, but United area starting to tick under Louis van Gaal and are one of only three sides to take points off Chelsea this season.

The Red Devils have racked up three consecutive league wins to start the fightback from a dismal start to the season and they may yet become title contenders, especially if a lengthy and damaging injury list clears up.

In contrast Chelsea have suffered few injury problems so far, despite Costa being hampered by a hamstring problem, which may flare up again and could leave the Londoners struggling to find adequate cover.

The Blue half of Manchester will also not be giving up the fight just yet, with City the current Premier League champions another of the teams to secure a draw against Chelsea this season.

The Citizens have also made an inconsistent start to their title defence, but are almost certain to be there or thereabouts coming the closing weeks of the season, especially given their hunting down of Liverpool last season when all looked lost.

And added to domestic factors, there is also the small matter of the Champions League, which must be somewhere near the forefront of Mourinho's mind.

The Portuguese has already won the competition with FC Porto and Inter Milan and is desperate to make history and be crowned European master with a third club, having missed out during his first spell in charge of Chelsea.

Three wins and two draws have seen the Blues book their place in the knockout stages of the Champions League already and, having come so close and failed, Mourinho may be tempted to trade domestic glory for European success if push comes to shove.

So there are a number of reasons why Chelsea are nowhere near home and dry in the Premier League just yet, but you can bet your bottom dollar that Mourinho is more than happy to have his challengers on the back foot and facing a stiff test to try and derail the Blues bandwagon.