Alex Telles's agent is reportedly confident that Manchester United will make a formal bid for the Porto defender before the transfer window closes.
The Red Devils have missed out on the signing of Real Madrid's Sergio Reguilon to Tottenham Hotspur and are running out of time to land a new left-back.
Brazil international Telles has been touted as a possible alternative for United and, according to Portuguese outlet A Bola, agent Pini Zahavi is expecting to hold further talks with the Premier League side.
Porto are said to be willing to do business with United and are looking to land around £18m for the 27-year-old, who has spent the past four years at the Estadio do Dragao.
Luke Shaw is Ole Gunnar Solskjaer's current first choice at left-back but has struggled for form and fitness during his time at Old Trafford.