Benfica star Pablo Aimar is convinced they can defeat Chelsea in this week's Europa League final.

The Blues won last ­season's Champions League, but Argentine midfielder Aimar says times have changed. "Of course, Chelsea are a big club, but this is not the same team that won the Champions League a year ago," said the 33-year-old. "This team got knocked out at the group stages. They have not been ­convincing in ­Europe or in the Premier League.

"Since they have inherited a wealthy owner, this is probably the weakest Chelsea team there has been.

"And it is a team that is not behind the coach. We can take advantage of the fact they are not at their best and not playing as a team.

"Chelsea lost two great players in ­Didier Drogba and Michael Essien.

"Then players who have been so ­important like John Terry and Frank Lampard are not even getting games.

"It is amazing how much a team can change in 12 months, but that is ­football," Aimar added.