Robin van Persie's Manchester United exit should worry fading Wayne Rooney

Sunday 12 April 2015, Robin van Persie is at Old Trafford watching behind glass as United dismantle City in the derby, capping off a flurry of impressive results in the league in a tricky spring period. He looked every bit the little boy referenced when he signed three years prior, a far cry from the subsequent unplayable and ultra-professional debut season. Three months later, Van Persie, Louis van Gaal's compatriot and captain last summer in Brazil, is being sold to Fenerbahce, reportedly earning the player - 32 next month - a potential four-year contract.

The decision to sell this summer appears to be a sensible one. Van Persie does not look like he will recapture the form displayed in that season for the striker. Understandable - he was magnificent. Ineffective for much of last season, with injuries only excusing a portion of another problematic spell on the back of an unedifying campaign under Moyes. But equally, one more season for the Dutchman under the Dutchman would not have been a surprise either - and now we come to the crux.

Ruthlessness, decisiveness, foresight, whatever. It's a strong decision from Van Gaal and it's been swift and painless from the outside looking in; no apparent fallout or protracted struggle. Does it send a message? Hopefully. More pressingly, United need goals, arguably more than they need a defence, and they are looking a bit Steve McClaren up top even for a team predominantly playing one striker at a time. An increasingly high-pitched Hernandez doesn't look like he's coming back or wanted and, beyond Rooney, there is James Wilson. Wilson should score goals for fun (an odd phrase) and, all being well, was being shielded somewhat last season, but it is hard to tell. Even in ideal circumstances usurping Rooney is tough for anyone, let alone a 19-year-old.

Unveiling Memphis Depay on Friday, Van Gaal hinted at the possibility of the winger being used as a striker. While he is certainly flexible by all accounts, it's hard to imagine him spearing the attack alone, particularly when United are desperate for his creativity and speed out wide. If a big striker comes in, things get interesting and it doesn't look beyond Van Gaal to do what Ferguson surely intended to when it suits.

As for Rooney, his record as a United player is first rate, nearly undisputedly so. He was a wonderful player who had a blistering hat-trick debut against Fenerbahce over ten years ago and never looked back. Also not in dispute, he is no longer the same player and, with some summer acquisitions, should never be needed again in midfield for any stretch. He is still a good player. Last season he even showed resilient qualities as a captain, and you can imagine him being a popular personality (yes, really - amongst footballers) off the field. Plenty of plus points and more caveats than a discussion about Michael Carrick. Plenty of worries too; his touch is awful at times, he seems to make United stodgy more often than not and it increasingly seems he burnt brightly early and hasn't taken care of himself sufficiently. The service from midfield is improving therefore a striker is not required to continually fall back in search of the ball. Put bluntly, Rooney needs to lead the line and score goals, and if he's unable, United cannot afford to carry him.

Whether that happens this season remains to be seen and part of Rooney's success last season as captain was due to the lack of other leaders in the team. United are likely to be losing another in Rafael, admittedly absent already, and with it more of United's identity. That Ander Herrera now

gives the impression of an established player at Old Trafford is telling of the current flux - consequently, new leaders are emerging not from within, despite the manager's insistence on Friday he wants to promote rather than buy. If Van Gaal wants a title-winning striker he may also require a new captain soon.