Boudewijn Zenden, of Middlesbrough, has suggested he may leave the Riverside this summer to further his club and country ambitions if the side do not qualify for Europe again.

Boudewijn Zenden, of Middlesbrough, has suggested he may leave the Riverside this summer to further his club and country ambitions if the side do not qualify for Europe again.

Steve McClaren's side go into the return leg of their last-16 tie in the Uefa Cup against Sporting Lisbon tomorrow on the brink of bowing out of the competition following a 3-2 first-leg defeat. They have also slipped out of the top six in the Premiership due to a run of results which has seen them take just seven points in nine games since the new year.

With Zenden, who becomes a free agent in the summer, unable to make any impression on the Netherlands manager, Marco van Basten, despite 55 caps to his credit, he appreciates a fresh start could be the answer if he is to play in the 2006 World Cup finals in Germany.

"It's true that for me it's important to be playing in Europe," Zenden said. "I've not looked too much into the future as yet, but if we were able to qualify for the Uefa Cup then that is something that could influence any decision I make.

"I am really enjoying my time with Middlesbrough, which is an important factor for me, and is something I can take with me in making a decision. But I am still very ambitious. I still

want to play at the highest level and for the national team, with my goal to play in Germany in 2006 and I will do everything within my powers to convince the manager I should be there."

Boro's hopes have been hit by injury problems. The latest came yesterday with Zenden's fellow Dutchman Jimmy Floyd Hasselbaink sustaining a knee injury in training, ruling him out of the trip to Lisbon and, potentially, Sunday's league game against Southampton.

Hasselbaink joins Mark Viduka, George Boateng, Ray Parlour, Michael Reiziger, Gaizka Mendieta, Ugo Ehiogu and Malcolm Christie on the sidelines.