Lee Cattermole admits Sunderland's survival chances look "very tough" following their defeat to Leicester, but vowed the Black Cats will fight on.
Sunderland's 2-0 defeat at the King Power stadium left them bottom of the Premier League and eight points from safety with eight games left to play.
Islam Slimani and Jamie Vardy's second-half goals compounded a difficult few days for David Moyes after he received criticism over the weekend about comments he made to a female reporter following a post-match interview last month.
Moyes' side host Manchester United on Sunday, live on Sky Sports, and Cattermole said Sunderland must keep believing they can stay up.
"It looks very tough but you don't become a footballer by shying away from things," Cattermole said after Sunderland's 20th league defeat of the campaign.
"Everyone has that drive, we need to look forward to Sunday, get ourselves going and show how much we care about the position we're in.
"We've got another game on Sunday, we have to show some pride, stand up and find out what we're all about.
"We can't make any excuses, I thought we were bang at it and we played well at the champions. We felt we were the better team but we're walking away with nothing."
The 29-year-old made his first start since September following a hip problem, after playing just three games this season.
"I felt fine," he added. "I've felt great in the last couple of weeks. It's tough coming back in the position we're in but I'll rise to it and give my best."