BOLO ZENDEN admits a decision on his Middlesbrough future is likely to be delayed until the summer - just as it was last year.

The ambitious Dutchman only signed a one-year deal in the summer, when he finally agreed to stay with the club after months of negotiations, and is free to leave for nothing come July.

Zenden is more than happy at Boro but is determined to work his way back into the Holland squad and views European football as paramount to an international recall.

That is why the club's current predicament has left the player's future up in the air again, with the midfielder suggesting he will be considering all options before deciding his next move.

After clinching their first trophy a little over a year ago, manager Steve McClaren attracted a number of high-profile signings in the summer in preparation for their first foray in the UEFA Cup.

This morning they fly out to Portugal for tomorrow night's second leg with Sporting Lisbon knowing that remains their last chance of silverware this campaign.

A long list of injuries - it lengthened on Monday when it emerged Jimmy Floyd Hasselbaink suffered a knee cartilage injury - has also led to Boro dropping out of the top six in the Premiership.

And Zenden, hoping to work his way back into the Dutch squad before next year's World Cup in Germany, revealed he intends to wait before committing to the club.

He said: "It is vital we qualify for Europe again. It is the thing that could influence any decision I make.

"I have not left yet and, like anything in life, you don't know what you are going to get. I am still very ambitious, I want to play top level football but the fact I am enjoying here it is very important for me.

"It is not just important for me but for the club.

"If we qualify again we make another step forward and we can attract players to go to another level.

"I have not looked into the future yet but I have signed until the end of season and my dad is my agent so if anything happens I will be first to hear about it. For the time being we will see how it goes."

Hasselbaink's injury, he had scans on the problem yesterday and could be ruled out for up to six weeks, comes at a time when Zenden has called for the strikers to be ruthless up front.

The task of grabbing the two goals, at least, that would claw Boro from 3-2 down against Sporting is likely to be handed to Szilard Nemeth and Joseph Job in the Estadio Jose Alvalade.

Mark Viduka, who has played just 21 of Boro's 42 games since his move from Leeds, continues to be troubled by a hamstring problem and will not be on his way to Lisbon - but is thought to be nearing a return.

Gaizka Mendieta, Ugo Ehiogo, James Morrison and Malcolm Christie are all ruled out long term but Zenden refuses to make excuses.

"This is our biggest challenge in Europe after the first leg we have to set the thing straight," said Zenden, whose midfield partners Ray Parlour (back), Michael Reiziger (ankle) and George Boateng are also doubtful for tomorrow.

"It is a massive task and a big challenge but a big one as well.

"It is a great stadium and it should be an attractive game and it is great to be playing in the UEFA Cup. We have to enjoy it and we want to continue in it.

"Injuries are starting to be the story of our season.

"We just keep losing players and we can talk about the ones who are not there and that would keep us occupied but it is more important to talk about the ones who are here.

"I've never experienced an injury situation like this. I would like to think we have still got the players here who can get us through. We can still do it."

Sporting also have their own injury problems with both Custodio (knee) and Fabio Rochemback (thigh) out. Rochemback missed Sunday's 2-0 home defeat to Penafiel.

Superliga top-scorer Liedson should be fit despite complaining of a knee problem. Zenden said: "They lost at the weekend so things are possible and that is the way to approach it.

"We are the underdogs, they don't expect anything from us and they might think it will be an easy game and a nice evening in their lovely stadium but we will make sure it is different."

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