Derby defender Jason Shackell will miss the rest of the Championship season after having surgery on a back injury.
Shackell has not featured since the Rams’ FA Cup defeat by Premier League side Leicester in February.
The 33-year-old, who joined Derby from Burnley in July 2015, made 10 appearances for the club this season.
“It was something that needed to be done to clear up what has been a long-term issue,” manager Gary Rowett told the club website.
“The plan is for him to come back for pre-season training ready to go.
“Speaking to him about it, he felt as if he was playing at around 80 per cent in games and couldn’t sprint as well as he would like to.”