GEORGE Boateng last night delivered a chilling ultimatum to Middlesbrough's board as they begin to prepare for next season: "Improve the squad or I'm off."

The Dutch international, who has only recently returned to action after breaking his toe in December, will enter the final year of his contract at the end of the current campaign.

Steve McClaren is determined to tie him to a longer deal and, earlier this week, the Boro boss revealed that he had opened talks with both Boateng and his compatriot Bolo Zenden, who will become a free agent next month.

But, while Boateng has revealed that he is yet to make any firm plans about his future, the former Feyenoord star has hinted that he will be willing to walk if Middlesbrough's ambitions do not match his own.

"I expect the club to buy more players," said the 29-year-old, who will make his 100th Boro appearance on the final day of the season if he plays in every game between now and then.

"If we'd had more players this season, we would already have qualified for Europe.

"Because of a lack of strength and depth, we haven't been able to cope with the losses that we've had.

"It has been difficult. You can't expect to cope with 11 major injuries, but I think everyone expected us to bring players in to help us deal with the situation.

"When I got injured, the team was fifth in the league and, when the transfer window opened in January, I think we all expected new signings to come in to help the team progress.

"That didn't happen. I understand why they didn't buy players for the sake of it - you can't just take the second-best thing - but it was a surprise."

Boateng has become a pivotal presence in Middlesbrough's midfield since joining the club almost three years ago and, tellingly, the Teessiders won just two Premiership games from 12 during his recent lay-off.

McClaren is well aware of the midfielder's importance to his team and, over the next few weeks, he will attempt to persuade him to extend his stay at the Riverside.

At the same time, though, McClaren will be discussing his own future.

The England number two is also out of contract next summer and, with Sven Goran Eriksson expected to stand down at the end of next year's World Cup, speculation is mounting over his own long-term plans.

Boateng is desperate to see McClaren commit himself to the Middlesbrough cause but, should his manager opt to leave the club in the future, he is sure that many of his team-mates will follow the Boro boss' lead.

"It is important to see who is going to leave and who is going to come in," said Boateng.

"And it is also important to see whether or not the manager is going to stay and how long he's going to stay for.

"The manager is the person who started all this. It is very rare to be able to work with an international manager on the club scene.

"Most of the time, the people you are working with are trying to get to that level. He's already there and he transfers his experience from the England set-up to Middlesbrough.

"He's a great manager and it's great to have him here. When he goes away to internationals with England, we miss him.

"It's very important that he stays - I think some players might choose to leave if he departs."

European football will also play a prominent role in Boateng's decision, and Boro will take a huge stride towards guaranteeing more continental competition should they beat relegation-threatened West Brom this afternoon.

Tuesday night's disappointing 1-1 draw with Fulham left Boro two points adrift of a UEFA Cup spot and, after making their European bow this season, there will be some furrowed brows should the club miss out next term.

By applying for the Intertoto Cup, Boro's board have sought to provide a fall-back plan should results not go in their favour this month.

But, instead of offering an alternative route to Europe, Boateng sees the much-maligned competition as a headache rather than a cure.

"The question of Europe is very important to me," he revealed. "But I am not so positive about the Intertoto Cup.

"I have been there twice and, on each occasion, I have had to buy a new pair of legs by the time January has come around.

"I couldn't walk any more after January, couldn't even pass the ball for three or four yards.

"It will catch you up. I am not a big fan, and I would like to say to every Premiership manager 'Do not get into the Intertoto'.

"Our league is too strong and too hard. You are playing a lot of games - in the league and the two cups - and, if you are an international, it is even worse. You barely have a rest.

"It can be a great pre-season. It is a great way to get fit and your first six months will be magnificent because of the Intertoto Cup.

"Your footballing levels and skills will be a lot higher than they would be without it.

"But then you will need to buy a lot of new players in January because the ones you have will be exhausted."