Southampton's Shea Charles and Leicester City defender Ben Nelson are both on the club's radar.
The Daily Mail reported both interests on Thursday, with the club viewing Charles and Nelson not as frontline signings but as high-potential options at lower price points who can contribute to a group expected to play more than 60 games across all competitions next season.
Charles, 22, is a Northern Ireland international defensive midfielder who came through Manchester City's academy and was signed by Jason Wilcox — Manchester United's sporting director — during his time at Southampton. The athletic midfielder was a consistent performer for the Saints across three Championship seasons and helped them reach the play-offs before the Spygate scandal resulted in their expulsion from the post-season. United viewed Charles as a "high-potential option who would come at a lower cost."
Southampton's exclusion from the play-offs and subsequent four-point penalty for next season makes Charles's departure from St Mary's considerably more likely. His market value is understood to be around £25 million.
Nelson, 22, is a 6ft 5in centre-back and England Under-21 international at Leicester City, who were relegated to League One this season. He can also operate at left-back and is praised by those who have coached him for his pace and reading of the game. Enzo Maresca, the incoming Manchester City manager who previously managed Nelson at Leicester, is also understood to be an admirer — which adds competition to United's pursuit.
Chelsea had also tracked Nelson, meaning a competitive process is likely if United make a formal approach.
United's primary midfield business involves more expensive targets. Ederson from Atalanta is close to being confirmed as the club's first summer signing, while Sandro Tonali of Newcastle United and Middlesbrough's Hayden Hackney are also on the list. Manuel Ugarte is expected to be sold to fund further activity, with Casemiro already confirmed as a departure.
Carrick's experience at Middlesbrough in the Championship has given him familiarity with the quality level available in English football's second division — a factor that may have informed the identification of both Charles and Nelson as viable options.