To say Wayne Rooney has underachieved on his talent is to accept his talent compares to that owned by Lionel Messi, Cristiano Ronaldo and perhaps every player bar one who put on a Manchester United shirt before him.
Rooney hasn't scaled the heights of Messi or Ronaldo. He won't go down as a peer to Sir Bobby Charlton or Eric Cantona in the affection of United fans, and his genius is not in the George Best league. But he should be remembered as a United great, whatever happens next.
Let us not confuse the Rooney who fell flat at World Cup 2010 and made little impression at Euro 2012—England's brightest, most frustrating prospect for a generation—with the force of nature who has won a Champions League, five Premier League titles and scored 197 goals for his club (Manutd.com).
Only Charlton, Denis Law and Jack Rowley have prompted the celebration of United fans more times.
To label Rooney anything other than a success at Old Trafford is to ignore the heavy weight of evidence. Without him, Sir Alex Ferguson's teams of the last nine seasons would have been short 156 Premier League goals and 86 assists (Premier League).
How many players in the world could have contributed at that level, with that consistency? It's hard to think of many, if any, outside of Messi and Ronaldo.
But there remain nagging doubts over Rooney's mentality and his consistency. The street-fighting footballer has honed his raw ability and become an accomplished player at the very highest level, yet there were times last season Ferguson thought his team were better off without him.
Rooney was dropped at the start of the campaign, having returned from his summer holiday overweight (Metro). He didn't start for United's biggest game of the season, away at Real Madrid in the Champions League, for tactical reasons. In six of his last eight games, he was either a substitute or substituted for—only twice playing the full 90 minutes.
That just doesn't happen to the elite players we might consider in Rooney's class at Europe's top table. Little wonder Ferguson said the 27-year-old was "frustrated" as the season drew to a close (Yahoo!). Little wonder he has asked for a transfer.
Deserved or not, it can't be easy for a player of Rooney's temperament and reputation to find himself sitting on the bench or pulled from the field in the midst of a battle. Rooney will be desperate to avoid a similar fate next season, and the smart move is to leave United behind.
Some will argue he should stay and tough it out, but patience has never been Rooney's strong suit. Should he stay and find himself behind Robin van Persie, Shinji Kagawa and whomever David Moyes brings in this summer, Rooney may struggle to keep his feelings bottled. Nobody would benefit from a mutiny, not least Moyes as he succeeds the greatest club manager in history.
If Rooney leaves now, he can do so with dignity and a fine United legacy behind him. There will be fans who resent his going, but in time they will reflect on a player who lent his considerable gifts to their club and provided considerable entertainment along the way.
The one-club approach works for some players, but in the case of Rooney, a new environment may be exactly what he needs to become the player we always thought he would be. A new challenge, in a new league, would instill a new sense of purpose in him.
Maybe he's gotten too comfortable at United. Maybe he's stopped developing as a player. Maybe the learning process needs to start all over again.
Rooney needs to change something or risk seeing out the remainder of his peak years without truly touching the heights he's capable of. A move would be a risk, but the potential reward is his further evolution and the chance to truly claim his place among the best players in the world.
When you weigh the pros and cons, it's a risk worth taking.