Sunderland suffer second injury set-back ahead of Sheffield United clash as Alex Neil confirms Daniel Ballard blow
Ballard was forced off after nine minutes on Saturday after fracturing his foot in the Black Cats' dramatic 2-2 draw against QPR.
Neil has not put a timescale on the injury but the Northern Ireland international is expected to be out for approximately two months.
Now Winchester is set to see a specialist regarding a back problem and Neil lamented: "When it rains, it pours."
Sunderland are unbeaten in their opening three Championship games and are one point ahead of the Blades heading into tomorrow's game.
"Unfortunately for us, at the moment, Winnie [Winchester] is injured, so he's out for a little while," said Neil as he prepares his side for the clash in South Yorkshire on Wednesday evening.
"I think he's due to see the specialist tomorrow, so we'll get a better idea of that one then.
"That's why, at the moment, he isn't in contention for a role in the back line. It's a problem with his lower back and we'll find out the full extent once he's seen the specialist."
Winchester played in last week's Carabao Cup defeat against Sheffield Wednesday but was absent from the matchday squad against QPR.
Neil admits he could be forced back into the market following the injury problems.
"Dan has been a key signing for us, he's got mobility, he's good on the ball, big and strong, his best years are ahead of him. He's everything we want in a signing," he added.
"Realistically, those players are really, really hard to come by, particularly for what we can afford.
"I could give you a list of players right now - in fact I've got a list in my drawer - but the difficult part is considering what you can get for where we are, and what we're trying to do."