Acquisitions up front and in midfield raise questions as to where the captain may fit in as Mourinho pursues a serious push for the Premier League title.
Given that Ibrahimovic is an A-list No9, Anthony Martial’s suitability there and the emergence last season of Marcus Rashford, Rooney’s days appear numbered in the position.
No10 seems the captain’s spiritual home. Yet Mkhitaryan is a dynamic, quick, creative footballer who can operate across the front and is a natural playmaker.
The 27-year-old made his name out wide in the past three seasons at Borussia Dortmund, switching between left and right. The Armenia captain, though, often operates in a central role for his country, and at Shakhtar Donetsk from 2010-13 he did the same.
Two days after he was signed on 6 July for around £30m, even the United website ran a feature entitled: “What is Mkhitaryan’s best position?”
Mourinho’s answer will be of interest to Rooney. The manager, who takes charge of United for the first time on Saturday in a friendly at Wigan Athletic, seemed clear in his first public comments on where Rooney will line up. He swatted aside the fact Louis van Gaal had deployed the 30-year-old as a deep-lying midfielder, a move followed by Roy Hodgson in England’s calamitous Euro 2016 campaign.
“Maybe he is not a striker, not a No9 any more, but for me he will never be a No6, playing 50 metres from the goal,” Mourinho said. “You can tell me his pass is amazing but my pass is also amazing without pressure. To be there and put the ball in the net is the most difficult thing. For me he will be a nine, a 10, a nine and a half – but never a six or an eight.”
Examine these comments more closely and they become less black and white. Rooney may never be a six or an eight but after Mourinho states he is possibly not a centre-forward any more, he contradicts himself by saying “he will be a nine, a 10, a nine and a half”. The sense here is that as the season develops Mourinho feels he may require a shoehorn to fit Rooney into his strongest XI.
Leaving aside the question of what a “nine and a half” may be, it seems that when United travel to Bournemouth on 14 August for their season opener, Rooney will be in the side as the No10, Ibrahimovic the No9 and Mkhitaryan on the right, with Martial on the left.
A born winner, Ibrahimovic is sure to shake up the United dressing room and act as Mourinho’s on-field general. This should be a fillip for a side who have no Champions League football and who need to make a serious push for the title.
Yet the leadership detail is supposedly the domain of Rooney as captain and club totem. He will continue to wear the armband but how the Ibrahimovic-Mourinho love-in that dates from their 2008-9 season together at Internazionale may affect Rooney’s mood and status could be a developing situation.
The arrivals of the Swede and Mkhitaryan also concern Jesse Lingard, Memphis Depay, Juan Mata, Ander Herrera, Ashley Young, Adnan Januzaj, Andreas Pereira and James Wilson.
Januzaj, Wilson, Pereira, Herrera, Depay and Mata may leave or fade from the first-team picture. Young, Lingard and Rashford look to be understudies to Martial, Mkhitaryan and Ibrahimovic. Ibrahimovic is 35 in October but can expect to be sent out on most game days and certainly on the seismic ones – think the 172nd derby with Manchester City at Old Trafford on 10 September.
Mourinho has also signed Eric Bailly, 22, from Villarreal and the Ivory Coast centre-back and Marcos Rojo are expected to deputise for Chris Smalling and Phil Jones, who have been informed they start the term as the first-choice pairing.
The will-he-won’t-he saga of Paul Pogba may be a further reason why Rooney is not required in midfield. The latest word coming from the Frenchman’s agent, Mino Raiola, is that Pogba could stay at Juventus as “he is not desperate to move”. Given Raiola’s penchant for harnessing the media for his endgame this may be the latest step in prising Pogba from Juve.
If the 23-year-old arrives he will be an automatic choice. He would partner either Michael Carrick, after Mourinho handed the midfielder a fresh one-year deal, or Bastian Schweinsteiger, who impressed for Germany at Euro 2016. Morgan Schneiderlin appears to be a reserve, at best.
As it stands, the defence would be Matteo Darmian, Smalling, Jones and Luke Shaw, with David de Gea in goal. Daley Blind, a Van Gaal favourite who operated mainly at centre-back and left-back, could be squeezed out, unless Mourinho decides Blind can join Schneiderlin as central midfield competition. Darmian’s deputy should be Timothy Fosu‑Mensah, the 18-year-old who impressed during his 10 appearances last season after making his debut. Cameron Borthwick-Jackson, 19, who played 14 times last year in his debut season, is Shaw’s No2.
Shaw is in line to make his comeback from a broken leg on Saturday at Wigan. There, Mourinho, the third United manager in four seasons, starts his quest to lead them into a post-Sir Alex Ferguson era of sustained success.