Patrick Vieira has warned Manchester City to expect a United backlash at Old Trafford on Saturday.
The clubs go head-to-head this weekend, seven days after Sir Alex Ferguson's men lost their unbeaten league record at Wolves.
It was a result that allowed Vieira's old club Arsenal to trim United's lead at the top of the Premier League to four points, while City closed to within five, but if the Blues feel their neighbours will be easier to overcome on Saturday lunchtime now they have tasted defeat in the league, Vieira has warned them to think again
"We must expect a backlash and a battle," Vieira told Abu Dhabi-based paper The National. "Big clubs like United always talk about the importance of never losing two times in a row. They will want to bounce back to winning ways immediately."
For Vieira, any meeting with the Red Devils inevitably brings back memories of his personal feud with Roy Keane, which memorably reached its nadir in the Highbury tunnel in 2005 as the teams were waiting to come out onto the pitch before kick-off.
The sight of the two warriors finger-jabbing told its own story of their commitment to the cause and, though Gary Neville's loose tongue was said to have started it, Vieira still admires the newly-retired full-back.
"He had a fantastic career," Vieira said. "I respect him because he had been at United his whole career and he won trophies and was a permanent fixture in the starting XI.
"Yes, I had a problem with him, but I had a problem with a lot of players."
How many more of these matches Vieira will be involved in remains to be seen.
"I have six months left and am enjoying my football, but I have to be realistic," he said. "I'll be 35 next season and I know it will hard to play every game. I have to see if I am willing to accept playing only one or two games every three or four months."