The Premier League giants are focused on snaring Frenkie de Jong away from Barcelona and are preparing to table a second bid for him soon.
But negotiations and moves for other targets are simmering as well and Manchester United are putting in the legwork on a few other deals.
Erik ten Hag wants a centre-back and Martinez and Torres are the two defenders Manchester United are looking at closest.
And according to Dutch daily the Algemeen Dagblad, Martinez is the defender Manchester United would prefer to sign over Torres.
The Ajax defender has already worked with Ten Hag and Manchester United are reportedly preparing a €40m bid for him.
Talks have also taken place between Manchester United and Torres’ representatives but the Argentinian is their clear preference.
Martinez has one other suitor in the Premier League in Arsenal who are said to have failed with a €30m bid.
Manchester United are hopeful that the prospect of being under Ten Hag again will be more of a pull for the Ajax defender.
