PETER Gentle says he doesn't know when Hull FC will see Daniel Holdsworth back in action after the stand-off was ruled out with a head injury.
Holdsworth missed Saturday's 18-18 draw at London and Gentle revealed the Aussie has been stood down because of serious headaches.
Concussed at St Helens in round three, Holdsworth is still feeling the effects five weeks later and has seen a neurosurgeon, but tests have provided no solution.
Worried about causing further problems and with no clear solution, Gentle has told his key playmaker to rest up, ruling him out of a crucial Easter period including Friday's derby, and no return date's in sight.
"Daniel is still having some side effects from the concussion," said Gentle. "He won't be back for the derby, I've no timeframe though."
"It's pretty serious when you have a head injury that goes on this long. We have to be smart with it and he has to be smart with it too."
"We've stood him down for a few weeks and hopefully we'll get a result out of that."
Holdsworth missed rounds four and five in the aftermath of his injury, but was back in the team for the victory against Castleford and defeat at Huddersfield.
Most notably the stand-off didn't complete either game and was visibly sick coming off the pitch at Huddersfield.
"He's been passed fit each time to play, but then around the 60-minute mark he starts getting headaches," explained Gentle.
"He's been for all the tests, seen neurosurgeons and everything. Each time he plays it's coming back."
While Hull will be without Holdsworth for the Good Friday derby, full-back Shannon McDonnell is expected to return after a hamstring pull saw him miss the match in London.
"Shannon twinged his hamstring during the week," said Gentle.
"He would have been touch and go but he definitely wouldn't have played if he'd come and we'd seen the ground like this," said Gentle.
"We rested him up and he should be fine for Friday."
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