Ole Gunnar Solskjaer should shortly be asked about the well-being of Harry Maguire and Luke Shaw, but the Manchester United manager's fitness bulletins have a tendency to be about as reliable as the former health secretary's daily Downing Street briefings.

Solskjaer's kidology is ineffectual, particularly as the Manchester Evening News almost always publishes the full United squad. Shaw is believed to have been unwell on Saturday, although it is possible he sustained an injury that forced his removal against Aston Villa. Maguire appeared to suffer a calf injury that was possibly impact-related from a tangle with Danny Ings.

If both are unavailable against Villarreal on Wednesday night, Raphael Varane would be the only first-choice member of the United back four in the XI, with Aaron Wan-Bissaka suspended. Diogo Dalot, an encouraging performer of late, is already certain to start.

United have drawn all four of their Champions League encounters with Villarreal 0-0 and the Europa League final was a 1-1 draw over 120 torturous minutes. A scan of Villarreal's form this season is cause for dread: seven draws - four of them goalless - and one win.

Villarreal have primarily played in a 4-4-2 formation but switched to a 4-3-3 for the weekend's goalless draw against Real Madrid. Madrid had 14 attempts to Villarreal's five and were restricted to two attempts on target. United recorded the exact same statistics in Gdansk four months ago.

Despite gaps of nearly 16 years and 13 years, Unai Emery's Villarreal is not dissimilar to Manuel Pellegrini's Champions League novices that United faced in 2005 and then in 2008. Obdurate and compact, Villarreal have only conceded six goals this term and Solskjaer lauded the performances of centre halves Pau Torres and Raul Albiol back in May.

"When they've got Torres and Albiol in there on crosses it's always going to be difficult," Solskjaer said. "We needed to play our way into the box quicker." Albiol joined Real Madrid in the same summer as Cristiano Ronaldo and it is a matter of time until Torres moves to one of Europe's elite.

Cavani came on against Villa
Cavani came on against Villa

Solskjaer failed to make a single outright attacking substitution against Villarreal and at the weekend belatedly plumped for Edinson Cavani. That was not the most strategic of choices, for United appeared to switch to a 4-4-2 without natural wingers to service their two marksmen, guarded by a defensive trident.

Gary Neville was chided by Jamie Carragher on Twitter for including Cavani and Ronaldo in his best United XI on Monday. "Ossie Ardiles wouldn’t pick that team," Carragher laughed, a reference to the Argentinian's gung-ho approach as Tottenham manager in the 90s.

There is merit in starting Cavani and Ronaldo against Villarreal to duel with Torres and Albiol, as long as United have a specialist winger. That would mean a recall for Jadon Sancho, maybe on the right to offer natural width, which would possibly prolong Paul Pogba's stint on the left. Dropping Mason Greenwood would be harsh, though his selfishness at times was costly on Saturday.

Solskjaer paid Villa and Young Boys an excessive amount of respect and the suspension of the Villarreal midfielder Francis Coquelin invites United to play a more expansive side. Gerard Moreno, the joint-second highest scorer in La Liga last season, has missed Villarreal's last three matches with a hamstring strain.

Whatever the formation, Nemanja Matic and Donny van de Beek would be logical selections. United were devoid of creativity in centre midfield against Villa and they will need a fifth forward if they are to breach Villarreal at the fifth time of asking in the Champions League.

United have to use the Villarreal fixture as an experiment to galvanise their domestic form. Everton, due at Old Trafford at Saturday lunchtime, have favoured 4-4-2 this season and retained the set-up without the sidelined Richarlison and Dominic Calvert-Lewin in their last two league games.

Everton have as many points as United and Villarreal a point more, cause for Solskjaer to make deferential selections, especially if Wan-Bissaka, Maguire and Shaw are all absent. Solskjaer is more cautious than carpe diem with his tactics but it has to be the other way round this week.