Failure to find a way past the Wearsiders would see the knives really out for the beleaguered former Everton boss .
The Wearsiders have been anchored in the bottom three virtually all season and are without a win at Old Trafford since 1968 .
Failure to find a way past the Wearsiders , who have been anchored in the bottom three virtually all season and are without a win at Old Trafford since 1968 , would see the knives really out for the beleaguered former Everton boss .