Paul Butler, the Leeds United captain, suffered a suspected fractured foot in last night's 2-1 defeat at Cardiff and faces several weeks on the sidelines.

Leeds will assess the extent of the central defender's injury today but the initial signs are not good.

Butler looks certain to miss Saturday's trip to Luton and it will be a big personal blow if he has to miss the home game against his old club Wolves on Saturday, August 20.

His absence should mean a run in the side for York-born Matthew Kilgallon alongside Sean Gregan, with Clarke Carlisle having left to join Watford in a £100,000 deal.

Kilgallon replaced Butler for the second half last night and conceded the penalty which brought Cardiff's 67th-minute winner from Darren Purse after Bluebirds substitute Jason Koumas had celebrated his debut by cancelling out Robbie Blake's opener.

With Steve Stone, Rob Hulse and Ian Moore already injured and Blake defying an ankle knock to play last night, the last thing Leeds needed was another injury - especially to a player of Butler's enormous influence.

Assistant manager Sam Ellis said: "Paul's foot is badly bruised and may be fractured. We will find out more when it is thoroughly examined.

"We were very disappointed with the result at Cardiff and our second half performance. Maybe we became a bit complacent after taking the lead. 'Killa' said the ball hit him on the hand, but if the ref sees it as a penalty there is nothing we can do."

Sheffield United's fine start to the Championship season continued with a 2-1 win against Burnley at Turf Moor.

Neil Shipperley took four minutes to open his Blades account, finishing from close range after good work from strike-partner Danny Webber.

Veteran centre-back Chris Morgan sealed the points before the break with a tame finish from a corner at the second attempt, making it maximum points from two games for the Blades.

Promoted Luton, whom Leeds visit on Saturday, are the only other team with maximum points after beating Southampton 3-2.

:: Leeds match facts

Coca-Cola Championship

Cardiff City 2, Leeds United 1

(at Ninian Park)

Cardiff City: Alexander, Darlington, Purse, Cox, Barker, Ardley, Boland (Koumas 56), Whitley, Cooper (Mulryne 90), Jerome, Parry (Lee 86). Subs not used: Warner, Loovens. Cautions: Purse, Jerome. Goals: Koumas 60, Purse 67 (pen).

Leeds United: Sullivan, Kelly, Butler (Kilgallon 45), Derry, Harding, Lewis, Bakke, Gregan, Wright (Richardson 76), Blake, Healy (Ricketts 63). Subs (not used): Bennett, Einarsson. Cautions: Butler, Derry. Goals: Blake 22.

Referee: S Tanner (Gloucestershire)

Attendance: 15,231

Updated: 10:47 Wednesday, August 10, 2005