Christopher Samba says he was ashamed of QPR's performance against Swansea, a game they lost 4-1.
Samba, 28, was one of two high-profile signings the club made in the January transfer window, but despite claiming a goalless draw against Norwich on his debut the club remain rooted to the bottom of the Premier League.
"I have nothing to hide - I was very angry," he told the club's official website. "I said what I saw to the players. You shouldn't be ashamed of your performances but against Swansea, I was ashamed of both mine and the team's performance. There's nothing worse than feeling full of regret."
The only player who came away from the game with any credit in Samba's eyes was striker Bobby Zamora who came off the bench to score Rangers' only goal.
"Bobby Zamora showed us what the Premier League is about when he came on," he said. "I think more of the players should have his attitude - urgency that reflects we have 12 games left and must play every one like a cup final. We have to give everything."
Despite their lowly position in the league table, Samba is hopeful of following up the draws with Tottenham and Manchester City and the win against Chelsea by pulling off a shock against Manchester United on Saturday.
"We all want to beat Manchester United," he said. "We've worked hard for two weeks in the lead up to the game and we want to get a result. But whatever happens, we need to show great attitude and commitment on the pitch. We have quality, but we also have to show desire."