United are looking to sign a new centre-back this year and retain an interest in Villarreal star Torres a year on from considering him under Ole Gunnar Solskjaer.
The Manchester Evening News understands initial talks have taken place to gauge the possibility of a move for Torres and that the transfer has also been discussed internally with Ten Hag.
The 25-year-old was placed on a five-man shortlist as United looked for a centre-back last year, and was viewed as the back-up option during their successful pursuit of Raphael Varane from Real Madrid.
Torres still has a release clause in his current deal, which is in the region of 60million after he penned a contract extension until 2024 three years ago. Last year, Villarreal were open to a possible player-plus-cash offer for Torres, although their priority would be to sell him for cash only.
Ten Hag has championed Ajax defender Jurrien Timber during initial recruitment meetings, and the club held exploratory talks with Antonio Rudiger's representatives before he opted to join Real Madrid.