How Man Utd's pursuit of Saul Niguez began six years ago

Manchester United are long-term admirers of Atletico Madrid midfielder Saúl Ñíguez.

He is a player who would enhance their squad and now that the 25-year-old Spain international is being linked with a summer move away, it is no surprise to see United listed among the possible destinations.

It would not be the first time United have had the talented player on their radar.

Back in 2014, the Irish Independent reported on a low-key scouting trip, led by Phil Neville, to watch Saúl in action.

At the time he was on loan at Rayo Vallecano, still an inexperienced youngster attempting to prove himself and earn a regular starting spot under Diego Simeone at Atletico.

He was also a target for both Arsenal and Chelsea in 2014, but Atletico opted to keep hold of the promising teenager, despite their then reputation as a selling club.

Neville and the United staff turned their attention to Ander Herrera, who would eventually join United and they also monitored Isco.

Koke, another coming Atleti star who was then in his early 20s, was another player United's scouts were said to be keeping a keen eye on.

Six years on, Saúl has established himself as one of Europe's most coveted midfielders after making almost 300 appearances for Los Colchoneros and impressing in their Champions League success home and away over holders Liverpool last month.

He signed a nine-year contract with the club in 2017, and the length of that deal and his loyalty to Simeone's team could prove to be sticking points in any potential transfer.

Atletico, now among Europe's richest clubs, are not as willing to sell their best players as they once were, but suitors may be willing to pay the £135m required to sign Saúl.

Saul's performance in that last-16 Champions League victory over Liverpool has been cited as the catalyst for United's potential renewed interest.