After the first week of the 2009-10 English Premier League, what have we learned about the likely title contenders? Well, as Wolves manager Mick McCarthy told journalists on Tuesday, it’s not like we didn’t already know this league had big teams with big players.

While bookies’ favourites Chelsea may have been somewhat fortunate to grab an injury time winner at home to Hull in their opening fixture, there was nothing lucky about their 3-1 away win against Sunderland with Ballack, Lampard and Deco all on the scoresheet. With Drogba signing a new deal and Carvalho seemingly happy at Stamford Bridge despite rumours he would be reunited with old boss Jose Mourinho at Inter Milan this summer, it seems the Chelsea camp are a settled bunch under new supremo Carlo Ancelotti.

While Chelsea have kept their stars (for now), the focus of attention for some teams at the top has turned to those who haven’t. There was no doubt that the result of the week came at Turf Moor, where newly-promoted Burnley shocked reigning champions Manchester United 1-0 thanks to a stunning volley by Robbie Blake. It was the first time United had lost to a promoted team since 2005 (against Norwich), but it was Michael Carrick’s penalty miss that prompted the inevitable question: How are United going to cope without Cristiano Ronaldo?

It’s still far too early for any team to be pressing the panic button, but Ronaldo’s fancy boots are big ones to fill at United, and the likes of Nani, Anderson and newcomer Antonio Valencia will have to raise their games against the likes of Burnley if they are to convince the Old Trafford faithful.

Similar questions were being asked of Liverpool following their below-par performance against Tottenham on the opening weekend. Without influential playmaker Xabi Alonso – who followed Ronaldo to Madrid – who will provide Gerrard and Torres with a defence-splitting pass from midfield? It certainly doesn’t look like coming from Mascherano or Lucas, yet it was right-back Glen Johnson, the England international who signed from Portsmouth in the summer, who provided their only spark against Spurs. Johnson was on the scoresheet as Liverpool got back on track with a 4-0 victory over Stoke, but all Reds fans will be worried if anything happens to either Gerrard or Torres this season.

Arsenal, the other member of the so-called ‘Big Four’, have lost the likes of Emmanuel Adebayor and Kolo Toure (both to big-spending Manchester City), but they showed no signs of missing their stars with a 6-1 away win at Everton – who themselves are expecting their influential leader Joleon Lescott to join City’s revolution.

Many experts predicted Arsenal are the more likely team to slip outside the Champions League places at the expense of Manchester City, Aston Villa, Everton or the rapidly improving Tottenham. Their performance on the opening day suggested they have adjusted to their losses this summer much better than United or Liverpool.

How those two respond after their shocks this week will provide interesting viewing for the rest of us.