We will be joined by Chelsea, Birmingham and an as yet unconfirmed Asian club.
It is likely that the Singapore Tournament will be followed by a friendly against Chinese champions Dalian Shide in Hong Kong.
United chief operating officer Russell Cushing told the Evening Chronicle: "It's the inaugural year for the tournament and it is hoped that it will go on to become an annual event in that part of the world.
"It is being backed by the Premiership and we have qualified because we were in sixth place in the table on December 4."