Former Chelsea star Marcel Desaily reckons the club is missing the dynamism of Michael Essien in midfield after letting their early advantage in the Premier League slip.Chelsea trail Manchester United as they travel to Old Trafford for a must win game after they had led for long spells this season.And Desaily is in no doubt the absence of Essien has contributed to the slump in form.“It looks like the [Chelsea] midfield have not really delivered protection to the defence," Desaily said. "The defensive block have had some problems this year. That is why they are not four, five or six points ahead because they have lost many points on free-kicks and just generally losing their concentration. Previously the midfield was absolutely amazing."Even if they weren't winning the Premier League, it was holding the team. The midfield was really playing well. Now Joe Cole is not expressing himself as he wanted, [Michael] Ballack has disappeared the last two months, [Jon Obi] Mikel is playing his best but the team misses Essien. So this is why the defence is suffering."Essien is hoping he can return to play a part in the final stages of the season but admits he has is not sure exactly when he will be playing again.Source: Kickoff.com