The Croatia worldwide has been linked with a move to Manchester United in the current transfer market after his impressive performances at the World Cup this summer.
Luke Shaw is prepared to walk away from Manchester United on a free transfer next summer if his first-team prospects at Old Trafford do not improve, sources have told ESPN FC.
The delay to Sanchez's arrival is a blow for Mourinho's planning for the U.S. tour, which gets underway with a friendly fixture against Club America in Glendale, Arizona on Thursday.
According to the BBC, the Chilean is now banned from entering the U.S. after accepting a 16-month suspended jail sentence for tax fraud in Spain in February.
A United spokesperson said: "Alexis Sánchez did not travel due to a personal administrative issue".
Persons found guilty of fraud can not be granted a visa to visit under United States law.
There is a waiver scheme and it is understood Sanchez is working with his lawyers in an effort to be granted access to the United States. But the process has taken longer than expected with the opening game scheduled in two days.
"If Manchester United, the most powerful club in the world, can't reach an agreement after eight months of negotiations, it means they don't really consider him to be an important player".
According to a Metro report, the 23-year-old finished top of the bunch when the United squad was put through its paces during a training session in Los Angeles on Tuesday.
Shock as Trump backs Putin over U.S. election meddling
Asked if Russian Federation was at all to blame for the poor ties, he said: "I hold both countries responsible". Trump also dismissed the idea in his interview with Hannity , adding, "If they had it, it would have been out".
Liverpool submit world record bid for new goalkeeper
Simon Mignolet , meanwhile, is expected to leave Anfield this summer after he lost his place to Karius last season. The 25-year-old stopper has spent two years in Italy following his arrival from Internacional in his homeland.