ALL eyes are on John Terry.

That's not the first time the Chelsea defender has become the focus of attention this season, although for once it has not followed a series of aspersions about his conduct. Terry has carried the weight of countless off-field controversies, all despite recurring injuries and fitness concerns.

He must shoulder the expectation of his club as well tonight. Chelsea face Benfica in the first leg of their Champions League quarter-final tie with Benfica, a side with a proven propensity for discomfiting sides from the Barclays Premier League. It was the Portuguese club whose 2-2 draw at Old Trafford in November contributed to Manchester United's Champions League downfall in the group stage.

It that result was titillating back then, it is now a source of some consternation for those at Stamford Bridge. They will now look to their embattled captain to quell their fears.

It is a familiar position for Terry to be in. He revels in it; he is as comfortable attending to the deficiencies of his own team as he is the forward incursions of an opposition striker. He is also just as adept at it.

Against Tottenham Hotspur on Saturday – a match which ended 0-0 – he was by general consensus the stand-out performer. Against Napoli in the home leg of the last-16 tie he was goalscorer, organiser, dogged defender, touchline tactician and chief cheerleader when he was substituted in injury-time.

That was Terry at both his best, and also his worst. Much was made of the fact he effectively took over from Roberto di Matteo – nominally the club's interim manager – going over the Italian's head, quite literally, by barking instructions and directing his team-mates. Even Di Matteo looked to the Englishman.

That vignette epitomised the problem with Terry. He commands almost unchallenged power within the Chelsea dressing room – which a number of managers have found to their cost, most recently Andre Villas-Boas. It is unlikely that the London club's travails will abate until he is deposed, along with the likes of Frank Lampard and Didier Drogba, or a manager is appointed that is strong enough to constrain them. It would take a Special One to do that, of course.

Villas-Boas had been brought in to break the grip that senior players had over the club. He failed. His cause was not helped by poor form and the sight of the club languishing in fifth-place in the Barclays Premier League, but his efforts to regenerate an ageing squad were undermined by Terry. The result was inevitable.

And yet you sense his club could not do without their talisman, not in matches like this. The defender leads by example, on the pitch at least, and he is a source of comfort and inspiration for his team-mates and supporters alike. Their plight has seldom been greater.

Chelsea are unlikely to finish in the top four and gain a Champions League qualifying spot this season, which means unless they defeat Benfica – and most probably Barcelona in the semi-finals –and then lift the trophy, there will be no Champions League football at Stamford Bridge next season.

That is the size of Chelsea's challenge. Those are the stakes Chelsea are playing for tonight against a Benfica side they are capable of overcoming, but who possess real threat in winger Nicolas Gaitan, Paraguayan striker Oscar Cardozo and their midfielders Maxi Pereira and Pablo Aimar.

Benfica, two-time winners of the European Cup, are also unbeaten in 10 European home matches. Benfica are on a roll. Chelsea, by contrast, are in danger of being rolled over. This term Terry has given plenty of reasons to suggest Chelsea could do without him, yet tonight they will discover just why they can't.