Boudewijn Zenden has signed a one-year deal with Middlesbrough.

The 27-year-old put pen-to-paper yesterday morning, with Boro attempting to get the deal tied up in time for him to appear in the friendly clash against Hansa Rostock today.

Zenden has been training with Boro all this week and passed a medical yesterday.

"He signed all the paperwork this morning," his father and agent Pierre Zenden said yesterday.

"It is open to be extended. He could do it after just two months if that is what is agreed."

Boro will unveil Zenden - their fifth signing of the summer - early next week, and he flew out with the rest of the squad to Germany yesterday, with the Teessiders hoping he is eligible to play some part in today's game.

Zenden starred on loan at the Riverside last season, scoring from the penalty spot in the Carling Cup final, and has since been released by Chelsea after being told he did not feature in new manager Jose Mourinho's plans.

Clubs in Spain, Holland and Turkey were keen to acquire his services but the signings of Mark Viduka, Jimmy-Floyd Hasselbaink, Michael Reiziger and Ray Parlour have persuaded him that his future also lies on Teesside.

Meanwhile, Malcolm Christie and Colin Cooper are struggling to be fit for the start of the season - with Cooper's career hanging in the balance.

Christie is still recovering from a badly broken leg and manager Steve McClaren confirmed he is not yet fit.

"Christie is working hard in rehab but it's still too early to say when he will return to training," said McClaren.

Cooper is struggling with a knee injury he picked up last season.

"I picked up the knee injury in a reserve game towards the end of last season. I had nicked the posterior ligament but had the knee cleaned up and expected to be okay," said the 37-year-old.

"That was almost three months ago and I'm still being troubled by it. The knee doesn't feel right and, if it continues to cause me problems, I may have to revaluate where I go from here.

"Perhaps it's my body's way of telling me that enough is enough - I'll just have to wait and see.

"But I'm not worrying. I've a had a great career and I know it's drawing towards a close."