A highly motivated, skilled and speedy Real Betis are the most dangerous opponents Chelsea face in their Champions League group, coach Jose Mourinho said on Tuesday.

The Spanish side trail European champions Liverpool and English champions Chelsea in Group G by just one point and know if they beat either English side they have a very good chance of qualifying.

Betis coach Llorenc Serra Ferrer promised before final training for Wednesday's game that his side would live up to expectations and play to win, not defend for a draw.

Mourinho, who worked with Serra Ferrer on the staff at Barcelona five years ago said: "The group is dangerous not because of Liverpool but because of Betis.

"They know if they come to Stamford Bridge just to defend it will be very difficult for them...and they will not want to lose their personality," he added, describing the Spaniards, spearheaded by international winger Joaquin and Brazil [Images] striker Ricardo Oliveira, as fast and attack-minded.

Liverpool have already beaten Betis but the Spaniards had a fine win over Anderlecht in Belgium, a feat they would hope to repeat at home.

Chelsea have taken three points off Anderlecht and drawn with Liverpool.

OPEN GROUP

"Everything in the group is open and it will be open until the end," Mourinho said.

Serra Ferrer said he saw winning as "something that is not impossible.

"Since putting Monaco out in the last round we have placed no limits on our ambition in the competition...All we can do is relax and play to the best of our abilities.

"We have the opportunity to qualify. If we did beat Chelsea we would have a very good chance."

The pressure is all on the English champions. Mourinho, desperate to succeed at Champions League this season after losing by a single disputed goal to Liverpool in the semi-finals last season, said Betis had quality and experience on their side.

"I like them. I like their way of playing. They have a lot of quality in attack," he said.

"Fourth in the Spanish league is better than champions in lots of other leagues," Mourinho added.

"For most of them it is the first time they are playing in the competition and they know that Chelsea have not lost this season. That will be a big motivation for them," the Portuguese manager added.

With Ireland's Damien Duff sidelined after knee surgery, Mourinho will choose two wingers from England [Images] pair Joe Cole and Shaun Wright-Phillips and Dutchman Arjen Robben, back in the squad after injury.

Argentine forward Hernan Crespo [Images] returns to the squad after a long journey home from international duty in Uruguay last week.

Mourinho, customarily reticent about his exact line-up, made one exception on Tuesday by announcing that Ghana's Michael Essien, embroiled in controversy over a tackle against Bolton last Saturday, would start.

The FA said on Monday they were studying footage of the incident but decided on Tuesday not to proceed with any charges.

Mourinho backed the midfielder he bought for 24 million pounds ($41.89 million) in August.

"He is a good player. He is a fair player with a good disciplinary record," Mourinho said.