The 28-year-old's current deal at Stamford Bridge expires in just over two years but under FIFA's rules he could buy out the remainder of the contract in the summer.

Neither Lampard nor his agent, Steve Kutner, have suggested the England midfielder is anything but committed to the Barclays Premiership champions, although no agreement has been made yet.

Lampard said: "It's down to the club to come to me with an offer, I'm waiting for that.

"There are a lot of things going on and we're at a stage of the season when it's important that the board of directors and the players concentrate on football."

Although there is the possibility of a clean sweep of trophies, Chelsea remain nine points behind Barclays Premiership leaders and their Champions League hopes were under threat last night when Porto took the lead at Stamford Bridge.

Chelsea boss Jose Mourinho, playing against the side he led to the European Cup in 2004, then made the bold move of taking off Claude Makelele for Mikel Jon Obi but the decision was vindicated by the Nigerian youngster's performance.

"He didn't very well and it was a good change by the manager," said Lampard after the 3-2 aggregate win put Chelsea into the quarter-finals.

"He got on the ball and moved it about, and allowed me and Michael Ballack to push forward in the midfield.

"That's what he can do. Jon Mikel has all the attributes physically and talent-wise to be a very good player. What he has to do is keep pushing himself to get there, because he's got it all."

Although it was Arjen Robben and Michael Ballack who scored the second-half goals against the Portuguese champions, Mikel's presence was considered the the catalyst for the turnaround.

It marked the next incident of the midfielder's colourful career to date, which has involved his controversial move to Stamford Bridge, accusations of a poor attitude, and a sending off against Arsenal in the Carling Cup final for his part in the infamous Millennium Stadium brawl.

"He didn't deserve it at Cardiff, that's for sure," added Lampard. "He's a physical boy who will put his foot in and might pick up yellows or reds.

"Technically he's very good, he's young but is already a good player and will be a very good player."

Meanwhile, Chelsea goalkeeper Petr Cech has spoken of his change in outlook since returning from the fractured skull he suffered against Reading in October.

He has only conceded five goals since coming back in January and is targeting his first Champions League final.

"We've been in the semi-finals and I hope we can do better this year," said the 24-year-old Czech Republic international.

"Maybe I'm enjoying the game more now after the most difficult moment of my life. It's always nice to have the chance to be on the pitch, it's as simple as that.

"Sometimes you play a difficult game or the weather is not good and you have to find the motivation - but I'm pleased in all conditions, against all opponents and in all competitions. I'm just pleased that I'm on the pitch."