Ole Gunnar Solskjaer is used to short-term fixes. As a Manchester United player, the Norwegian's introduction from the bench struck fear in opponents due to his knack of harrying tiring defenders and scoring crucial goals. He was regularly Sir Alex Ferguson's go-to man late in matches.
On his return to the club as interim manager, he will have to douse fires rather than ignite them and, if United are to become an appetizing prospect for managers like Zinedine Zidane and Mauricio Pochettino, show signs of a brighter future at Old Trafford.
Here is the job list Solskjaer must immediately tackle to clear up some of the mess left behind by Mourinho.
Mourinho wasn't always showcasing dour, unadventurous football. Early in the 2017-18 season, United set the pace with Manchester City at the top of the Premier League, scoring plenty of goals in the process. In their second game of that term, Mourinho let an incendiary trio of Romelu Lukaku, Anthony Martial, and Paul Pogba loose in the latter stages of a 4-0 win at Swansea City.
"The feeling was we can score more, so no need to close the doors. Just let the horses run freely. They were magnificent," he told BBC Sport after the match.
That certainly didn't reflect what happened for the rest of Mourinho's tenure, particularly in big matches. Lukaku was often marooned in attack and restricted to occasional touches, while the likes of Marcus Rashford, Alexis Sanchez, and Martial were frustrated in roles that (in true Mourinho fashion) often requested more of them defensively than offensively.
United's attacking talent can't continue to be wasted. Solskjaer needs to open those stable doors once again.
As a former forward himself, Solskjaer certainly appreciates the art of scoring, and oversaw Molde net a league-leading 63 times in 30 matches during the 2018 Eliteserien campaign. It was a welcome departure from previous seasons where his teams could seldom be described as free-scoring.
Perhaps the most notorious failure of Mourinho's Stretford spell was his inability to find a system that would get the best out of Pogba, and then his subsequent man management of the intelligent, irrepressible midfielder.
He was supposed to be the big signing to celebrate Mourinho's inauguration, but instead became a regular reminder of the Portuguese's tactical conservatism and poor handling of dressing-room personalities. The €105-million superstar sat on the bench in Sunday's 3-1 loss to Liverpool, and Mourinho never intended to play him. A criminal waste of a player who was influential in France's World Cup triumph over the summer.
At Juventus, he thrived on the left-hand side of a three-man midfield. He was sporadically deployed in that position for United, but was never afforded the freedom to roam, crack shots from afar, and catch out defenses with expansive deliveries into the frontmen. He wasn't allowed to exert risk under Mourinho.
Much like the attackers, Pogba needs to be liberated. He owns a rare gift of being able to single-handedly drag an underperforming team over the line, but hasn't been given the tools or encouragement to do so since returning to United in 2016.
Solskjaer showed he can shape a rigid backline at Molde, and that will be one of the first tasks on his agenda.
The solidity of Mourinho's rearguard ebbed away this season. In the 17 matches played so far, United have conceded more (29) than they did over the whole of last term (28). Aside from the goalkeeper, center-backs should be one of the consistent areas of the lineup, but Mourinho could never settle on a duo or trio between Eric Bailly and Victor Lindelof, or Phil Jones, Chris Smalling, Marcos Rojo, and ersatz options like midfielder Scott McTominay.
Once Solskjaer nails down his preferred defense, he should ensure it's organized. It was an ugly clutter against Liverpool and needs to be shaped into a discernible three or four with adequate communication and an actual inclination to press rather than just block. Despite Mourinho trying to indicate the contrary, Bailly is an excellent defender around whom this backline should be built around.
Nemanja Matic has been criticized this season, and it's deserved. His low speed at Chelsea and in the beginning of his United stay was compensated for by his tactical acumen and composure in a deep-lying midfield role, but his success rate with interceptions and creativity from deep has dipped in 2018-19. He is also robbed of possession with greater regularity.
There is still a quality player in Matic - his 2017 arrival was lauded as a masterstroke by many in the media, and £40 million for an experienced Premier League campaigner in this slot remains a decent deal - but he is looking weathered in his fifth consecutive season of regular first-team football and following World Cup participation with Serbia. The 30-year-old either needs more assistance from players like Ander Herrera or Marouane Fellaini in the middle, or simply needs to be replaced by one of them.
It will be interesting to see how Solskjaer sets up United. In his four wins to finish the 2018 Eliteserien campaign with Molde, he opted for a 4-2-3-1 formation that could warp into a 4-3-3 shape. This may be ideal: deploying Matic alongside a sprightlier teammate in the deep pivot, while freeing Pogba in dangerous positions between the oppositions' defensive and midfield lines.
There are certainly plenty of issues behind the scenes at Old Trafford, but Solskjaer has the apparatus available to construct a first team that will appeal to those under consideration to succeed him.