But Kirkland is now confident that he has seen the last of injuries for the time being, and can concentrate on his football again.
He told the club website: "The recovery is going very well. I had the operation on my back eleven weeks ago and it needed doing because I had been struggling with it for some time."
"The club and myself decided that the best thing to do was get it all sorted out so it's gone very well. I'm running again but I'm still a couple of week's away from diving and making saves but I'm hoping to be back in action this season," he added.
And Kirkland is desperate to get back into the action as soon as he is given his chance by Rafa Benitez.
"I hope to play before the end of this season, it's obviously up to the gaffer when I play but all I can do is get myself back and fit. If the manager wants me to wait and work more on my fitness then we will decide that later on."