Blackburn manager Sam Allardyce will miss Sunday's trip to his former club Bolton after it was revealed he would undergo an operation.
The 55-year-old has complained of brief episodes of chest pains in recent weeks and tests have revealed he requires an angioplasty - a procedure that involves inserting a stent to widen a narrowed coronary artery.
Allardyce will therefore miss Rovers' next three matches as he recovers from the operation with assistant manager Neil McDonald to take charge for the following games against Fulham in midweek and Stoke at Ewood Park next weekend.
The former Bolton boss, who spent eight seasons at the Reebok, is expected to return for Rovers' Carling Cup tie against Chelsea on Wednesday week.
"Sam is very disappointed, particularly at missing the Bolton fixture, but his well being is of prime consideration," Blackburn chairman John Williams told rovers.co.uk.
"We all appreciate that Premier League football is a stressful business and prevention is always better than cure."
In Allardyce's absence Rovers will aim to halt their horrendous Barclays Premier League away form.
Rovers have lose their past 10 league encounters on the road - shipping a whopping 18 goals in five matches this season - and while Allardyce will be missing, he hopes the atmosphere of a Lancashire derby can brew a change.
"For most of my football life I have been on the opposite side both as a player and a manager," said Allardyce, in his 12th month in charge at Ewood Park.
"I know the passion involved in a derby like this and I hope it is a spur for the players to deliver a result.
"Because it's time we changed the away form and time we put points on the board.
"There can't be a better time than going to our old rivals Bolton and doing that."
Allardyce will assess the emotional and physical effects of World Cup heartache on Keith Andrews before deciding on his side.
Andrews was in the Republic of Ireland team which controversially lost the play-off to France in extra-time on Wednesday, remaining on the field for the full 120 minutes.
Having also played the entire first leg in Dublin last weekend, Allardyce might feel it is too much for Andrews to slot back into midfield for the Barclays Premier League contest.
With Vince Grella (hamstring) now back to fitness, Rovers have a full squad to select from.
Bolton full-back Sam Ricketts is convinced his side can kick on and finish the season in the top 10.
However the Wales international believes it is imperative they bounce back against Blackburn.
Bolton have slipped down the league after the thumping by Aston Villa - shipping 15 goals in five league games - and Ricketts is anxious to make amends.
He said: "We are more than capable of finishing in the top half. We have had a hard run of games and our performances deserved more than what we actually achieved.
"It's time now to get those extra points and to start climbing the table. If we put a couple of back-to-back wins together then people will see us fly up the table."
Ricketts insists pride will be at stake when they face their neighbours and former manager Allardyce.
The Blackburn boss led the side into the UEFA Cup and also to the League Cup final during a successful eight-year spell in charge.
Ricketts said: "All derbies are big games and it's bragging rights as much as anything. It's putting one over your local rivals and the players feel that as much as the fans.
"You always want to win in general but the fact that it is a derby does add something to the game.
"Generally this season we have played well in the league apart from the game at Villa Park.
"It was one of those games where all of the outfield players had an off day and we need to write it off.
"But we can only do that by putting in a good performance and hopefully getting a win against Blackburn."
Bolton full-back Jlloyd Samuel is available again after suspension and he could replace Paul Robinson.
Manager Gary Megson will monitor the fitness of Tamir Cohen as the midfielder has a groin problem.
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