Manchester United FA Cup winner Paul McGrath has warned they must not take third round opponents Watford lightly this weekend.

McGrath wrote for the Sunday World: "Next Saturday Manchester United play Watford in the third round of the FA Cup - and, in different circumstances, it could have been the defining game in Ole Gunnar Solskjaer's tenure at the club.

"This same weekend 31 years ago the 'later-to-be-great' Alex Ferguson was in fear of being sacked as Old Trafford chief when a goal by Mark Robins against Nottingham Forest saw them squeak into the fourth round of England's famous club competition.

"The rest, as they say, is history.

"United and Ferguson went on to lift the trophy, then the European Cup Winners Cup the following season before adding to his trophy haul with the League Cup in 1992.

"One year later they won the first English Premier League and became the dominant force in the game for years to come.

"Unfortunately, I wasn't there for the glory years as I had signed for Aston Villa in 1989 - but I still feel the club is part of my bones and I love to see them do well.

"Manchester United's current place in the table insulates Solskjaer from fear of the sack next Saturday night.

"But the club needs a piece of silverware soon and they cannot simply discard the FA Cup by putting out a 'B' team. This is a match Ole will want to win."