Sinclair was handed a last-minute place in the squad after Danny Murphy pulled out through injury.
The West Ham player returned to England when Dyer's fitness was confirmed, but Murphy's broken toe meant he was quickly back on a plane to the Far East.
And Sinclair impressed during England's 1-0 win over Argentina after coming on as a 19th minute substitute following an injury to Owen Hargreaves.
The West Ham player is able to play on the right or left flank - where he played most of his game against the Argentines.
Sinclair made his international debut in a friendly against Sweden in November 2001.
Pacy, skilful and versatile, he can fill a number of positions should the need arise this summer.