Liverpool captain Jordan Henderson faces a long spell on the sidelines after undergoing an operation on the groin injury he sustained in last weekend’s Merseyside derby loss against Everton.

Liverpool has not put a timescale on the midfielder's recovery but said he will be out until at least April in another blow to its fading Premier League title defense.

“Henderson has successfully had a corrective procedure carried out on the adductor injury," Liverpool said in a statement on Friday. “He will begin a rehabilitation program immediately.”

Liverpool's Jordan Henderson walks from the pitch as he is substituted for an injury during the English Premier League soccer match between Liverpool and Everton at Anfield in Liverpool, England, Saturday, Feb. 20, 2021. (Lawrence Griffiths Pool via AP)

Liverpool's Jordan Henderson walks from the pitch as he is substituted for an injury during the English Premier League soccer match between Liverpool and Everton at Anfield in Liverpool, England, Saturday, Feb. 20, 2021. (Lawrence Griffiths Pool via AP)

Liverpool is in sixth place, 19 points behind leader Manchester City but the six-time European champions remain in the Champions League.

Henderson, who has been playing as an emergency center back, joins a lengthy injury list.

The three senior central defenders, Virgil Van Dijk, Joe Gomez and Joel Matip, have all had their seasons ended prematurely while backup Fabinho is still out, having played just one of the last seven matches because of a muscle injury.

Liverpool's Jordan Henderson lies injured on the ground and is attended to by a member of the Liverpool medical team during the English Premier League soccer match between Liverpool and Everton at Anfield in Liverpool, England, Saturday, Feb. 20, 2021. (Lawrence Griffiths Pool via AP)

Liverpool's Jordan Henderson lies injured on the ground and is attended to by a member of the Liverpool medical team during the English Premier League soccer match between Liverpool and Everton at Anfield in Liverpool, England, Saturday, Feb. 20, 2021. (Lawrence Griffiths Pool via AP)

James Milner is still sidelined by a hamstring problem and fellow midfielder Naby Keita only returned to the squad last weekend for the first time since mid-December. Forward Diogo Jota began full training this week after three months out with a knee problem.

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Liverpool's Jordan Henderson is hugged by Liverpool's manager Jurgen Klopp as he is substituted after an injury during the English Premier League soccer match between Liverpool and Everton at Anfield in Liverpool, England, Saturday, Feb. 20, 2021. (Paul Ellis  Pool via AP)

Liverpool's Jordan Henderson is hugged by Liverpool's manager Jurgen Klopp as he is substituted after an injury during the English Premier League soccer match between Liverpool and Everton at Anfield in Liverpool, England, Saturday, Feb. 20, 2021. (Paul Ellis Pool via AP)