Crystal Palace manager Oliver Glasner is still uncertain about how long Adam Wharton will be out of action.

The England international had successful surgery on his groin in November but struggled with pain upon his return to training last week.

Wharton’s discomfort meant that he had to step back from team training and return to recovery.

Glasner shared that the club must control the 20-year-old's tenderness before his return can be given the green light.

“It's not a structural injury. The structure isn't injured anymore because he had the surgery. This is prepared and done.

“With a groin injury, you have so many different types of muscles that are arriving in this zone.

“Sometimes it's here, it's there, it always going from left to right, from the bottom to the top.

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“It's not saying, okay, you put one injection and everything is fine because then there’s another spot where you struggle.

“We have to get the whole hip area under control and get everything working together.

“You have the back, you have the front, you have the adductors, you have the quad, you have the abdomen.

“There are so many muscles there and we haven’t been able to get them under control at the moment so that he’s is pain free. This is what we are trying.

“It’s difficult to say it's 'two weeks', it's 'four weeks'. But we need him back. Of course.”