Uefa Champions League:There may be a new management team at Stamford Bridge, but familiar frailties are threatening to undermine Chelsea's progress yet again. Avram Grant flew in to Gatwick early yesterday morning pondering the implications of the calf injury sustained by Petr Cech in Gelsenkirchen, the manager's gaze inevitably drawn to the crutches at the goalkeeper's side.

There is cautious optimism at Chelsea that, given proper rest during the forthcoming international break, the Premier League's best goalkeeper could be back within a month, to be joined by his captain, John Terry, once his knee has healed.

Yet even the remotest chance of having to play without either man would send shivers of anxiety through the squad. Grant is about to taste the frustration endured by Jose Mourinho during last season's trying campaign.

The Chelsea side robbed of Cech and Terry at the turn of the year did not lose any Premier League games, but their failure to retain their title for a third consecutive season was arguably born of the traumas suffered in that month-long period.

At a glance, a record of six league games yielding three wins and 12 points is hardly alarming. Indeed, Manchester United, the eventual champions, took only 13 points over the same period, so Chelsea hardly slipped from the pace in that time. Yet plain mathematics do not tell the whole story.

The absence of Terry and Cech to back and head injuries respectively was most keenly felt in the home games with Reading and Fulham over the festive period, when a normally miserly rearguard suddenly became vulnerable. Both visiting teams scored twice, and though Chelsea emerged with draws, they had effectively passed up four points. United suddenly led by six points.

Just as significant were the political ramifications. After the 2-2 draw with Fulham, Mourinho pointed to the void left by the pair and intimated it might not have been his choice to sell William Gallas and Robert Huth the previous summer. Mourinho said he needed extra defensive cover.

"We cannot defend, we concede incredible goals," he said.

The board was unimpressed and divisions between hierarchy and management deepened.

There is unity between Grant and the club's owner, Roman Abramovich, though the Israeli would recognise Mourinho's exasperation at being denied key players at an inopportune time. Chelsea were tearing up the table with four consecutive league wins and Cech was at his unflappable best. He had kept five consecutive clean sheets before the trip to Germany behind a defence that had, at times, been without Terry, Ashley Cole, Wayne Bridge and Paulo Ferreira.

Now he will be in the treatment room while his manager holds his breath. Carlo Cudicini is a fine replacement, but he does not boast the Czech's authority.

The onus now will be firmly on Ricardo Carvalho to maintain his impressive form against Everton on Sunday, though quite who will line up alongside him remains to be seen. Juliano Belletti was hapless at Schalke, and neither Alex nor Tal Ben Haim has impressed.

Options, yet again, appear limited. Much of Grant's onus has been on improving attacking play, though his priorities may be about to change.