Middlesbrough manager Gareth Southgate has confirmed that Robert Huth has suffered a fresh ankle injury.
Huth has suffered an injury-plagued time on Teesside since his £6million move from Chelsea in 2006.
The Germany international has been limited to just 23 league starts, but he looked to have put his problems behind him this season after starting the first six games with no problems.
But now Huth has damaged ankle ligaments, which will be a huge concern for Boro given he had to undergo ankle surgery last year.
"Robert has a problem with his ankle ligaments but we don't yet know the full extent of the injury," said Southgate.
"The area is very swollen and it's difficult to give an accurate assessment at this stage.
"However we should have a clearer picture by the end of the week."
With Emanuel Pogatetz suspended and youngster Rhys Williams already sidelined, Boro are left with few options other than Chris Riggott and David Wheater in central defence.
Jonathan Grounds, who was recalled from a loan spell at Norwich, can also play in the middle, but with Andrew Taylor also set for a time on the sidelines with a hip injury, he is needed at left-back.
Southgate is now keeping his fingers crossed that his international players return unscathed - last time round both Tuncay Sanli and Mohamed Shawky picked up injuries with their countries.
He added: "The international break wasn't too kind to us last time.
"We've got a lot of players away again this week. In fact we've got only six or seven left.
"Hopefully everybody will come back fine this time. After the win against Wigan, everybody will want to play against Chelsea."
Southgate confirmed that Tuncay could be back for the next Premier League clash with Luiz Felipe Scolari's leaders after his knee problem.
"The Chelsea game is one of Tuncay's targets but he will not be considered unless he is fully fit," he said.
"I can't say yet when he will be ready to start, but he should be very close by the end of next week. The week after is a more realistic target but we'll have to see."

Stoke 1-0 Portsmouth - Fuller and Sorensen
Tottenham 9-1 Wigan - Defoe
Stoke 1-0 Portsmouth - Pulis
Stoke 1-0 Portsmouth - Shreeves' blog
Stoke 1-0 Portsmouth - Hart
Tottenham 9-1 Wigan - Redknapp
Tottenham 9-1 Wigan - Martinez
Bolton 0-2 Blackburn - Megson
| Time | Fixture |
|---|---|
| Wednesday 25th November | |
| Barclays Premier League | |
| 19:45 | Hull vs Everton |
| 20:00 | Fulham vs Blackburn |
| Saturday 28th November | |
| Barclays Premier League | |
| 15:00 | Blackburn vs Stoke |
| 15:00 | Fulham vs Bolton |
| 15:00 | Man City vs Hull |
| 15:00 | Portsmouth vs Man Utd |
| 15:00 | West Ham vs Burnley |
| 15:00 | Wigan vs Sunderland |
| 17:30 | Aston Villa vs Tottenham |
| Sunday 29th November | |
| Barclays Premier League | |
| 12:00 | Wolverhampton vs Birmingham |
| 13:30 | Everton vs Liverpool |
| 16:00 | Arsenal vs Chelsea |
| Saturday 5th December | |
| Barclays Premier League | |
| 12:45 | Portsmouth vs Burnley |
| 15:00 | Arsenal vs Stoke |
| 15:00 | Aston Villa vs Hull |
| 15:00 | Blackburn vs Liverpool |
| 15:00 | West Ham vs Man Utd |
| 15:00 | Wigan vs Birmingham |
| 15:00 | Wolverhampton vs Bolton |
| 17:30 | Man City vs Chelsea |
| Time | Result |
|---|---|
| Sunday 22nd November | |
| Barclays Premier League | |
| Bolton 0 - 2 Blackburn | |
| Tottenham 9 - 1 Wigan | |
| Stoke 1 - 0 Portsmouth | |
| Saturday 21st November | |
| Barclays Premier League | |
| Liverpool 2 - 2 Man City | |
| Hull 3 - 3 West Ham | |
| Chelsea 4 - 0 Wolverhampton | |
| Sunderland 1 - 0 Arsenal | |
| Man Utd 3 - 0 Everton | |
| Birmingham 1 - 0 Fulham | |
| Burnley 1 - 1 Aston Villa | |
| Monday 9th November | |
| Barclays Premier League | |
| Liverpool 2 - 2 Birmingham | |
| Sunday 8th November | |
| Barclays Premier League | |
| Hull 2 - 1 Stoke | |
| Wigan 1 - 1 Fulham | |
| Chelsea 1 - 0 Man Utd | |
| West Ham 1 - 2 Everton | |
| Saturday 7th November | |
| Barclays Premier League | |
| Aston Villa 5 - 1 Bolton | |
| Blackburn 3 - 1 Portsmouth | |
| Tottenham 2 - 0 Sunderland | |
| Wolverhampton 1 - 4 Arsenal | |
| Man City 3 - 3 Burnley | |
| Pos | Team | P | Pts |
|---|---|---|---|
| 1 | Chelsea | 13 | 33 |
| 2 | Manchester United | 13 | 28 |
| 3 | Arsenal | 12 | 25 |
| 4 | Aston Villa | 13 | 22 |
| 5 | Tottenham Hotspur | 12 | 22 |
| 6 | Manchester City | 12 | 21 |
| 7 | Liverpool | 13 | 20 |
| 8 | Sunderland | 13 | 20 |
| 9 | Burnley | 13 | 17 |
| 10 | Stoke City | 12 | 16 |
| 11 | Fulham | 12 | 15 |
| 12 | Birmingham City | 13 | 15 |
| 13 | Everton | 12 | 15 |
| 14 | Wigan Athletic | 12 | 14 |
| 15 | Blackburn Rovers | 11 | 13 |
| 16 | Hull City | 13 | 12 |
| 17 | West Ham United | 13 | 11 |
| 18 | Bolton Wanderers | 11 | 11 |
| 19 | Wolverhampton Wanderers | 13 | 10 |
| 20 | Portsmouth | 12 | 7 |
Skysports.com looks at the best and worst moments from the latest round of top-flight fixtures.
Take a look back at what Liverpool and Man City fans had to say following a 2-2 draw at Anfield.
Bristol City fan Hannah Shine was strutting her as the Soccerette in the Soccer AM studios this week.
Jermain Defoe helped himself to five goals as Tottenham demolished Wigan 9-1 at White Hart Lane to move into fourth spot in the table.
Paul Hart played down the injury to David James prior to Portsmouth's 1-0 defeat to Stoke on Sunday.
Stoke collected all three points against Portsmouth thanks to a late strike from Ricardo Fuller.
Bolton squandered the chance to climb out of the bottom three as they were beaten 2-0 at home by Blackburn.
Tony Pulis put Stoke's poor first-half performance against Portsmouth at the Britannia Stadium down to nerves.