First come the trophies, then the tears.

There is a pattern that has followed Jose Mourinho throughout most of his managerial career - he wins everything in sight, makes enemies within and without and then exits under a cloud, leaving a trail of destruction in his wake.

The decision-makers at Old Trafford may be left asking themselves if the gamble was worth it after turning to the divisive Portuguese in their desperation to return to football's top table.

A seemingly proven British manager - David Moyes - and a safe pair of hands in the form of respected super-coach Louis van Gaal having failed, where else was there left to turn? 

A young tyro would be too much of a risk. Elite tacticians Carlo Ancelotti and Pep Guardiola had already been snapped up by Bayern Munich and Manchester City respectively.

Only one available man had the clout and winning pedigree to satisfy the growing unrest on the Stretford End, not to mention United's demanding commercial partners.

Executive vice chairman Ed Woodward has succeeded in propelling the club further into the stratosphere of endorsements and sponsorship deals but that has been despite, rather than as a consequence of, on-field performance.

Missing out on UEFA's elite competition for the second time in three seasons is unacceptable and continuing to do so will threaten to derail United's global economic juggernaut.

The team must start winning again and Mourinho has never failed to bring success to the major clubs he has managed.

The Primeira Liga, the Premier League, Serie A, La Liga and the Champions League are all proudly listed on the CV of the Portuguese.

However, if glory is guaranteed by hiring Mourinho then so, at some point, is disharmony.

Only at Porto and Inter did he leave from a position of strength and in a manner that could be described as amicable.

Three league championships and two sackings are his legacy at Chelsea, together with an on-going court case involving former club doctor Eva Carneiro, not to mention countless grudges, skirmishes and fallings-out. 

It was arguably worse at Real Madrid, where president Florentino Perez and his directors are likely to question if one Liga crown was worth the toxic atmosphere engulfing the club by the time Mourinho departed in 2013.

A venomous relationship with Barcelona coach Pep Guardiola, uncompromising tactics, the alienation of stalwart players such as Iker Casillas and accusations of UEFA conspiracies combined to leave the sourest of tastes in the mouths of Madridistas and neutrals alike. 

Suffering a similar fate is the risk United run by hiring Mourinho. 

Despite noted opposition from supporters to the Glazer regime in the last decade, United's administrators have excelled at staying on-message.

They have also stayed true to the club's tradition of promoting youth, evidenced by the emergence of a new home-grown generation headlined by Marcus Rashford.

Mourinho is notoriously distrusting of precocious young talent, while his record for playing attacking football is mixed at best.

Inter, Madrid and Chelsea could all score goals when they wanted, but making the game safe and avoiding risks always came first, as it will at United. 

Alex Ferguson himself may have been an occasional pragmatist, particularly in Europe. 

And, after the dark days of Van Gaal's reign, Mourinho's steamroller approach may prove a welcome diversion.

But the pressure is on both parties in this marriage of convenience. At 53 and after the worst period of his managerial career, Mourinho knows he must not fail at Old Trafford if he wants to remain one of the most sought-after coaches in world football.

By the same token the club, and Woodward in particular, cannot afford to make the wrong appointment for the third manager in succession.

A harmonious and entertaining march to success, powered by a sprinkling of academy graduates, is the desired outcome. It remains to be seen if that brief, particularly the unaccustomed role of diplomat, proves beyond the enigmatic, combative Portuguese.