Manchester United have made preliminary inquiries about a range of strikers including Alexis Sánchez, Jamie Vardy and their former player Javier Hernández as the club consider a move this window to give some back-up to Romelu Lukaku for the final months of the season.

The most eye-catching name is Sánchez, whose long departure from Arsenal is expected to be resolved this month with the favourites to sign him Manchester City, who came close to acquiring the 29-year-old in the summer. While City expect to get Sánchez, as of Thursday night there was no imminent sign of a deal and there are complications over the valuation of one of the Premier League’s leading talents who has just six months remaining on his existing contract.

United, whose players return from warm-weather training in Dubai on Friday, feel that Zlatan Ibrahimovic’s follow-up injury problems after his cruciate ligament injury have left them short of back-up for Lukaku, and that as a consequence his form is suffering. Mourinho prefers Marcus Rashford and Anthony Martial as attackers coming from wide positions which leaves them with what he considers a shortage of options in the central role.

Sánchez’s valuation is more difficult to gauge with City initially confident that a fee of about £25 million should do the deal but Arsenal are likely to want even more given their man’s pedigree. The Premier League leaders are still confident that they will sign Sánchez this window, although so far they have been resistant to paying the £35m Arsenal want, especially with wages for the player of around £250,000 a week.