DAVID BECKHAM (2003)
Another decision that left many a Reds follower heartbroken as one of our favourite sons was shipped out to Real Madrid, when many would have expected him to stay at Old Trafford for most, if not all, of his career.
The midfielder's celebrity status had soared to unprecedented levels, which presumably made managing a squad more difficult, and you only had to see the hullabaloo around the England international simply having a new haircut to sense his manager was losing patience. Warning signs were flashing when he was left on the bench for a key Champions League game against Real, only to come on and score twice, and, after being openly targeted by Barcelona, he instead joined their biggest rivals.
Just as Becks had more than made up for the loss of Kanchelskis on the right flank, the new Portuguese kid coming in to fill the gap thankfully did not do too badly either.
ROY KEANE (2005)
The inspirational skipper had given his all for the club and, by his own admission, put his body on the line for the cause. It was difficult for any United fan to think about him leaving and, when he did, it came so abruptly and with the sort of explosion that one supposes could have been expected of the firebrand midfield colossus. Following a spot on 'Play the Pundit', the MUTV series that analysed performances, it was a show that never aired, reputedly due to the nature of the criticism of his team-mates for a poor display against Middlesbrough.
The brilliant Irishman later acknowledged this was not the sole reasoning behind his exit, feeling there was a recognition he needed replacing in the engine room, but it was a divisive move that saw him depart for Celtic, even if he did later get granted a testimonial, in appreciation of his extraordinary contribution to our success.
RUUD VAN NISTELROOY (2006)
At the end of that season, the deadly Dutch striker was also deemed surplus to requirements and left, after being particularly upset to be left stewing on the bench for the League Cup final win over Wigan Athletic. Rowing with Sir Alex is never probably a good idea and there was a cloud hanging over him as his goal-laden Old Trafford career edged towards an acrimonious end.
Four years later, Ruud contacted his former manager to bury the hatchet and make up but the loss of one of our all-time great scorers was tough to take, coming at the end of the season when Keane had also exited. The hitman is simply one of those footballers who fans never wanted to see leave, with him joining Beckham at the Bernabeu leaving another bitter taste.