Sunderland boss Roy Keane admits it's back to basics for his team after this week's Carling Cup humbling at Luton.
The Black Cats face Manchester United this weekend and Keane told the club's website: "It looks as though Deano will need surgery in a couple of weeks.
"It's a bitter blow - we are missing his leadership qualities and his presence."
That was evident at Luton, the side they hammered 5-0 on the last day of last season as they clinched the title and Kevin Blackwell's men went down.
"We didn't do the basics right and we got punished for it," commented Keane. "If you don't do the basics you're never going to win a game of football.
"You've got to pass and move, you've got to defend properly and you've got to be physically strong.
"I'll analyse it, but I know we're short in certain areas and we're looking to improve, but I thought the players we had here were good enough to win the game and I take full responsibility for it.
"Last year everyone was celebrating, but I knew we had a massive job ahead and that has not changed. We're all in it together - when you start pointing fingers they usually start pointing back at you.
"Everybody was saying I was the greatest thing since sliced bread, but I never believed that for a second.
"The squad needs strengthening and we need a bit more physical presence. We've a tough game on Saturday and it's just a case of making sure we get the right team."