MARK Schwarzer has turned down Middlesbrough's offer of a one-year contract extension, but Gareth Southgate last night admitted he may be unable to offer the Australian the two-year deal he is demanding.

Schwarzer's current contract expires at the end of the season and Boro officials initiated talks over an extension earlier this summer.

In common with a number of their Premier League rivals, the Teessiders are reluctant to offer anything more than a 12-month deal to players approaching the age of 35.

Schwarzer, who turns 35at the start of next month, is demanding the security of a longer-term agreement.

But despite the Australian having spent more than a decade at the Riverside Stadium, Southgate is refusing to be rushed into tabling a two-year deal.

"We've offered Mark a contract and he knows we would like him to stay," said the Boro boss. "But he would like to stay longer than we've offered him at the moment.

"He wants to play through to the next World Cup (in 2010), so his concern is that if he signs a one-year extension and finds himself out of contract in the summer before the next tournament, it could affect his chances of being involved.

"I can totally understand where he's coming from and, as a manager, it's something I'm going to have to think about.

"Can I offer him that extra year that he wants? He's a fit lad but, when you're at the age that he is, none of us have a crystal ball to know how long players can go on for."

The impasse has created inevitable parallels with the protracted discussions that led to both Mark Viduka and Bolo Zenden leaving the Riverside Stadium for nothing, although Southgate insists will continue to pick Schwarzer while his future remains unresolved.

The shot-stopper remains Middlesbrough's undisputed number one and, after successfully shaking off a knee problem sustained during international duty with Australia, will retain his place between the sticks for tomorrow's trip to West Ham.

"There's no problem at all between us and we've discussed everything that's been happening," said Southgate, who is aware that Schwarzer will be free to talk terms with Boro's Premier League rivals if an agreement is not reached before January 1.

"He's a very professional person, and his performances and commitment to the team have been excellent.

"He's an outstanding goalkeeper and the understanding that we have is that we'll discuss the contract again a bit later in the year. He wants to focus on playing and put that to one side. With the type of professional he is, I'm happy to do exactly that."

Southgate also confirmed that former Newcastle United full-back Alessandro Pistone had trained with the Teessiders last week.

But while Boro are attempting to secure cover for first-choice left-back Andrew Taylor in the absence of the injured Emanuel Pogatetz, the 32-year-old Pistone was unable to fit the bill.

"He trained with us for a few days, but we weren't able to offer him a significant length of contract," said Southgate. "We were looking for a bit of cover because we don't have a natural left-back beyond Andrew Taylor, but we feel that one or two of the young players are doing really well at the moment so we decided to go with them."