Left-back Álvaro Carreras has been in sensational form for Benfica and his displays have alerted several teams, namely former club Manchester United as well as Barcelona, according to Sport. Barcelona are interested and could attempt to use Ansu Fati in a potential swap deal. Manchester United, meanwhile, need to strengthen the left-back position as a result of Luke Shaw's continued absence from the side, and former Sporting CP boss Ruben Amorim knows all about Carreras' ability from his time in Portugal. Record reported in October that United inserted a clause into Carreras' transfer deal enabling them to re-sign him for just €20m. According to TEAMtalk, Girona left-back Miguel Gutiérrez is another player on their radar.