Victor Valdes
The future of Victor Valdes at Manchester United has become uncertain nowReuters

Spanish international Victor Valdes was signed by Manchester United in January this year, but within six months, there is speculation about his future at Old Trafford. 

The former Barcelona custodian has not been included in the list of United players that left for the United States for this summer's pre-season tour.

What makes it more confusing is that the club have also reportedly not provided any reason for ignoring the 33-year-old goalkeeper. 

Sources at United have confirmed to British daily The Guardian that the Spaniard has simply "not been selected". 

It is to be noted that following his move to Old Trafford, Valdes was mostly relegated to the bench, and a player of his calibre didn't receive the amount of game time he deserved. 

Red Devils manager Louis van Gaal preferred using David de Gea as the number one keeper over the former Barca man. So much so that Valdes, who has a contract with the Old Trafford side until next summer, has made just two Premier League appearances last season.

This situation has triggered a new debate over the future of the Spaniard, setting off a transfer speculation.

The six-time La Liga winner with Barca received interest from Turkish side Antalyaspor this summer, a news that was confirmed by his agent. But he categorically rejected the offer he got for his client from Turkey.

"Some people from Turkey called me to negotiate Víctor's signing," Valdés' agent Ginés Carvajal told the Spanish daily AS.

"But I've never spoken to the president of that Turkish club. Hence, I'm not going to discuss the comments he made regarding Víctor. I don't know him.

"We have no intention of speaking to them again because the player does not want to go to Antalyaspor. His wish is to continue to play for Manchester United. He has one year left on his contract with the club. We don't see any just reason to leave the club.

"United is one of the best three or four clubs in the world. Víctor is enthusiastic to have a place in the team for next season and is ready to give his best to help the team much more," said Carvjal. 

Other players besides Valdes who are not included in the squad for United's tour of the US include Rafael, Reece James, Nick Powell. Robin van Persie is also left out ahead of his signing with Fenerbahce.

The only goalkeepers Van Gaal has at his disposal for the tour include De Gea, Anders Lindegaard, and youngster Sam Johnstone.

Van Gaal spoke to Manchester Evening News before heading to the US. He said that he is looking forward to taking a lot of youngsters with him for the tour with an aim to giving them the chance to prove themselves prior to the main season.

"You always get chances, especially in pre-season, and if you grab that chance then maybe you have the possibility to join our first-team squad next season," said the Dutchman. 

"I shall take a lot of youngsters with us to the USA and they have the chance to show themselves and then we shall wait and observe how they can develop."

Meanwhile, all of United's four summer signings so far - Memphis Depay, Matteo Darmian, Bastian Schweinsteiger and Morgan Schneiderlin - have landed in Seattle for the club's pre-season games.

United's opening game is against the Mexican team Club América in Seattle on Friday.