Victor Valdes is unlikely to be fit in time to deputise for David de Gea when Manchester United visit Arsenal on Saturday, sources have told ESPN FC.

Valdes, 32, has been training with United as he continues his rehabilitation from the cruciate knee injury he suffered in March while at Barcelona, and Louis van Gaal could sign the goalkeeper if he proves his fitness after eight months on the sidelines.

De Gea, 24, who is the Red Devils' only ever-present this season, suffered a dislocated finger when training with Spain last week and is a doubt for the Premier League clash at the Emirates Stadium.

However, sources said that while Valdes tweeted last week that he is "almost ready" to return, he remains injured and so United are unlikely to rush to sign him in time for a debut appearance against the Gunners.

That means Anders Lindegaard, who has not played for United since April, is in line to make his first appearance under Van Gaal, unless De Gea is deemed fit enough to start.

De Gea missed Spain's 3-0 Euro 2016 qualifying victory over Belarus on Saturday and is expected to sit out Tuesday's friendly against Germany as well.

United would be allowed to sign Valdes outside the transfer window because he has been a free agent since it closed in the summer, although they would have to apply for permission to include the player in their Premier League squad should they want to play him before January.

Such amendments can only be granted by the league body if a club have room in their squad to include an extra player -- but the Red Devils only named 24 senior players when their squad list was submitted to the Premier League in September, meaning there is one vacant spot which Valdes could occupy.

Valdes, who won six La Liga titles and three Champions League crowns during his 12 years at Barcelona, left the Camp Nou in the summer.

He attracted interest from Liverpool before Van Gaal, who gave the goalkeeper his Barcelona debut, invited him to train with United.