Middlesbrough striker Mark Viduka has suffered a setback in his battle against a hamstring injury.

The 29-year-old Australian, who picked up the problem during the 2-0 defeat at Birmingham on Boxing Day, was recovering well but has had to put his comeback on hold.

''Mark was progresing well, but he has suffered this unfortunate setback which has put his rehabilitation back another couple of weeks,'' said manager Steve McClaren.

''Mark is keen to be back as quickly as possible, but the most impotant thing is making sure he is right and fully fit before he can resume first-team football.''

Viduka had targetted the second leg of the club's UEFA Cup clash with Austrian side AK Graz on February 24 but now faces a longer wait despite already missing Boro's last nine games.

Boro have won just three of those and only two in the Barclays Premiership without the man recruited at a cost of £4.5million during the summer to partner Jimmy Floyd Hasselbaink.

McClaren was unable to call on either of his first-choice strikers for last Saturday's 1-0 home win over Blackburn - their first in the league in 2005 - after Hasselbaink was forced to sit out with flu.

However, he should be fit to resume at Bolton this weekend and could be joined by defender Chris Riggott, who has been out for five weeks with a hamstring problem.

Both men have returned to full training this week and could feature at the Reebok Stadium.

''It is welcome news and naturally we are delighted, with all the injuries we have suffered recently, that two key players can return to the first team,'' said McClaren.

Boro have been plagued by injury problems this season and McClaren has admitted if it were not for the strength of the club's Academy - which provided eight members of his squad last weekend - they could have been in trouble.

Midfielder George Boateng will see an orthopaedic specialist for a check on his toe fracture on Monday, although he will remain on the sidelines for some time, as will central defender Ugo Ehiogu, who is due to have his knee ligament injury assessed in two weeks' time.

Colin Cooper is expected to return to training some time next week after his knee problem, while Gaizka Mendieta, whose season was brought to an end back in October by ligament damage, is undergoing rehabilitation in his native Spain.

The former Lazio star is due to return to Teesside early next month to complete his recovery.

l New Celtic signing Craig Bellamy is hungry for his first taste of Old Firm action.

The Wales international is expected to face Rangers at Parkhead on February 20 in a game likely to have a major say in the destiny of the Bank of Scotland Premier League crown.

And the striker, who was loaned out from Newcastle following a bust-up with boss Graeme Souness, has also revealed he comes from a Celtic-supporting area of Cardiff.

He said: ''The area I am from is real Celtic.

''I don't want to go into it too much because I don't want to upset the other half but Celtic have a big say where I am from in Wales and a lot of my friends and family were delighted when I signed because it means a lot to them. I have always had a soft touch for Celtic.'