MIDDLESBROUGH manager Steve McClaren is weighing up his options after being rocked by the news that Spanish midfielder Gaizka Mendieta will miss the rest of the season with a serious knee injury.

The results from the scans Mendieta had on Monday have revealed he has ruptured the anterior cruciate ligament after going over under a challenge from Portsmouth's Patrik Berger on Sunday.

It is the same injury suffered by Juninho over two years ago when he missed the first six months of the 2002-03 campaign after arriving from Atletico Madrid.

The Brazilian travelled to the United States for reconstructive surgery and it is likely that, after allowing the ligament a few weeks' healing time, Mendieta will have to undergo a similar operation.

It is a massive blow to the 30-year-old, who had been hoping to force his way back into the Spain squad ahead of the World Cup in 2006 and was beginning to find his feet at the Riverside Stadium after a slow start to the season.

Mendieta, who once cost nearly £30m when he moved from Valencia to Lazio, will now miss next week's UEFA Cup group stage match with the Rome giants when the Italians visit Teesside next Thursday.

McClaren, whose side take on Championship side Coventry tonight in the Carling Cup, last night insisted the whole club are coming to terms with the fact they will be without one of their star men.

"The whole place is shocked by the news," said McClaren, who was the man who surprised the world of football when he snapped up the player on a free transfer in the summer of 2003.

"He is a massive influence on the way we play. He can unlock the door with a bit of cleverness. I'm more disappointed for him because he's just come back from injury. To deprive someone of playing football is very sad. Nobody likes to hear about it.

"He loves his football and this will be major blow to him. He's been a breath of fresh air to this club.

"He has taken to the Premier League and has become a popular figure and is a huge loss in this football club."

Mendieta is the latest in a long list of players - including Ugo Ehiogu, Michael Reiziger and Massimo Maccarone - who have suffered serious injuries during their time at Middlesbrough.

But, despite losing such an integral part of the starting line-up, McClaren believes it is now up to the other players to prove they can fill the void left by such a big football talent.

Ray Parlour, who has been playing in the middle of midfield until now, is one of those who could return to the role he played at Arsenal for a number of years by playing on the flank - meaning Bolo Zenden would drift inside and leave Stewart Downing free to play left-midfield on a regular basis.

But there is also the option of switching Szilard Nemeth to the right as well as giving Darlington-born teenager James Morrison more first team action after proving he can do a job at Premiership level against Manchester United and Chelsea.

McClaren, likely to hand Morrison the first chance to impress against Coventry tonight, said: "We have many men who will get an opportunity. We have options there in Ray, James and Szil.

"One of the main reasons we brought Ray here was that he could play in many positions. Whatever happens, we will have to move on and make sure that his loss is compensated.

"I can't believe how unlucky we have been with injuries. They have not been just little niggles, they are major injuries and players are out for months."

Middlesbrough take on Coventry at the Riverside as they begin their quest to retain the Carling Cup they lifted in February - the first time the club enjoyed success in a major competition.

McClaren - suggesting he will give Ehiogu and Andrew Davies starts after comebacks from injuries and fringe man Mark Wilson a taste of the action - insists he wants his men to go out and repeat the feat.

"The Carling Cup will always stay in the memory of all the staff, fans and players here. It's a big trophy for us," he said. "The first time in 128 years that this club won something and I have said since that everyone will be out to beat us.

"Peter Reid (Coventry's former Sunderland boss) knows all about Middlesbrough and our team. He's someone I admire greatly. He's having a difficult time of things but if anyone can turn things around he can.