Daniel Sturridge
Sturridge has been ruled out until early 2015 after suffering another setback in his recovery progress.Reuters

Liverpool have launched a thorough medical investigation to determine the reason behind Daniel Sturridge's regular fitness issues after the striker suffered a setback in his recovery for the third time this season.

The 25-year-old has been out of action since early September, after picking up a thigh strain while training with the English national team.

The former Chelsea striker was expected to make a comeback on 16 October, but he got ruled out for a further three weeks after suffering another injury during a training session at Melwood Park.

Sturridge was then expected to return to action during Liverpool's clash against Crystal Palace on Sunday, but he has been sidelined again until early 2015 due to a tear in his thigh muscle.

And Reds boss Brendan Rodgers is eager to find out why the striker keeps picking up regular injuries.

"Whether Daniel needs to see a specialist is something that the medical team are looking into," the Northern Irishman told Liverpool Echo. "I think that's his ninth injury on that thigh from previous clubs and here so there is an issue there somewhere.

"It's hugely disappointing to lose a player of that quality. It happened in a session and it was quite innocuous. He did it when he just flicked the ball, it wasn't a shot or anything that looked serious.

"Obviously he felt the pain and then when the medical team told me the next day after the scan it was disappointing. The scan shows a slight tear just below where he had a previous injury."

With the Reds currently struggling in the Premier League and other competitions this season, Sturridge's extended absence will certainly be a big blow for them especially with new signings, Mario Balotelli and Rickie Lambert, failing to make an impact so far.

But Rodgers insists that they will have to manage with the players who are available.

"Now we just have to concentrate and focus on the players we do have," Rodgers added. "It's that simple - make the best of what we have available.

"At this moment in time it's about what is within the squad because that's the players we have available." 

The former Swansea City boss also feels that this is a good opportunity for all the fringe players to prove themselves.

It will present an opportunity to the guys who may have been on the sidelines for quite a while. Now there's an opportunity for some players who didn't think they would get a chance."