Ruud Gullit believes Chelsea will need to have more than simply the physical power of Didier Drogba in their armoury if they are going to beat Barcelona and progress to the Champions League Final.

All the talk before tonight's game has been about how Lionel Messi could destroy the Blues' dreams. Yet, the 46-year-old Dutchman, who managed Chelsea between 1996-98, fears it is Chelsea, not Barcelona, who have become a one-man team.

It is no coincidence that since manager Guus Hiddink took over from Luiz Felipe Scolari in February and brought Didier Drogba back into the fold the Blues have once again looked like genuine contenders for European club football's top trophy.

While an improved team work ethic has contributed to their progress, the fact Drogba has scored in five consecutive Champions League games has been the real catalyst for their surge into contention.

The Ivorian's form has helped them get past Juventus and Liverpool, but Gullit (right) believes more players need to make their mark against Barcelona if they are to reach the final.

He said: "If you're the Barcelona coach, you are thinking 'if we eliminate Drogba a lot of the danger is already gone'.

"Chelsea rely on him too much. If he is not in good shape, Chelsea struggle a little bit. You could see that the moment he came back from his bad form, Chelsea's performances and results picked up again. If you depend too much on one player that is not good.

"Of course Frank Lampard is scoring his goals also and playing a big role, but they need to have more people making an impact. Players like Michael Ballack and Nicolas Anelka need to step up more in this tie. Barcelona are also very strong in midfield and Chelsea have to battle in there. They need to stop the players who pass the ball to the strikers, like Xavi. A lot of danger comes from him."

So far Chelsea have a defeat and two draws to show for their recent efforts on foreign soil, and it may take their best-ever performance to avoid starting the rematch at Stamford Bridge next week facing a deficit.

However, it was only three weeks ago that they were paired against another of Europe's in-form teams and outclassed them on their own pitch.

Hiddink sent his side out to go for goals rather than sit back at Anfield and the subsequent 3-1 first-leg win over Liverpool set up this semi-final - and Gullit believes his compatriot should employ the same tactics again.

He added: "Sometimes you have to grab the opposition and take the game by the throat. That's what they did that night. The strongest part of Barca is their attack, not their defence. Therefore Chelsea need to attack their defence a lot, put them under pressure.

"We all know when Barcelona have the ball they can do whatever they like with it. You don't want that. If they can't sit on the ball and have a nice decent build-up, they will get nervous and make mistakes."

Even then Gullit, who is currently considering a few offers to return to management but is hoping for a job in the Premier League, is worried it will be Chelsea's players who will have the biggest problem with anxiety.

While many of the current Barca side lifted the trophy in 2006, for long-serving Chelsea stars such as Lampard and John Terry this will be a fifth semi-final in the last six years and a winners' medal has so far eluded them.

They came within the width of a post during a penalty shoot-out against Manchester United in the final last season, but Gullit fears time is running out for the current squad.

He said: "Every time they go to the final or the semi-final it is hard for them psychologically. They have been close so many times and still haven't won it. That will be at the forefront of their minds."

Chelsea's players won't be the only ones keen to prove a point, with Thierry Henry looking to demonstrate to the English TV audience that he is back to his best.

The sight of him being used as a token substitute in both legs of Barcelona's semi-final defeat to Manchester United last year was a humiliation, considering what the Frenchman had achieved during eight years with Arsenal. But he has scored 23 goals this season and won over the initially-sceptical Barca fans.

Gullit said: "Henry has developed himself well. He came in a new situation where in the first year he wasn't playing particularly well, but all of a sudden, he found his way.

"He owes his whole career to England, but he will want to show everyone that he made the right decision."

* Ruud Gullit will be appearing on Sky Sports 2 tomorrow as part of their coverage of the other semi-final between Manchester United and Arsenal.