Chelsea manager Jose Mourinho has faxed a letter to UEFA pleading with them not to punish his old club Porto after he was spat at by a visiting fan at Stamford Bridge.

Mourinho is keen to preserve good relations with Porto fans ahead of the return match on December 7th.

It is understood he wrote to UEFA chief executive Lars-Christer Olsson yesterday pointing out their exemplary behaviour in the past and asking for leniency from the disciplinary committee.

The incident occurred during the warm-up before Chelsea's 3-1 win and was mentioned by UEFA's match delegate after being reported to him by referee Herbert Fandel.

The fan was ejected from the ground and hosts Chelsea are not expected to face any repercussions but UEFA have opened a disciplinary inquiry against Porto.

Under normal circumstances Porto would be fined but Mourinho's intervention could lead UEFA to take a different approach. Mourinho brushed off the incident after Chelsea's win saying: "I had my back to the crowd as I was watching my players warming up when it happened. I just went over to greet the supporters, but this is a normal thing.

"I can understand it. Some people love me, and others don't love me that much. But that's just life.

"The opposing fans do this many times. Unfortunately, these things happen.

"But there were also many people who wanted photos and paid me compliments."

Meanwhile, striker Alexander Frei returned to the Switzerland squad yesterday for their World Cup Group Four qualifier against Israel in Tel Aviv on October 9th following a two-game ban for spitting.

Frei has not played for Switzerland since being suspended from international football by UEFA for spitting at England midfielder Steven Gerrard during Euro 2004 on video evidence.