The young Black Cats striker has had a superb 12 months, as he shines for England at the Toulon Tournament.
The 21-year-old headed the opener in the 2-1 loss to Mexico, following up his goal in the draw with Morocco last week.
Their last game is against China on Friday, with a win a must to have any hope of progressing to the next round.
The youngster was awarded the Barclays Under-21 Player of the Season award, given out to the young man who most impressed the Premier League's Under-21 managers in the development leagues.
Watmore arrived at Sunderland from Altrincham in 2013, and made his first team debut in the FA Cup tie with Carlise last season.
The Mancheser-born forward was on loan at Hibernian at the start of 2014, where he scored once in 9 appearances, but returned to Sunderland to shine for the second string, where he scored 11 times in 19 games this year.
Watmore will now look to make his Premier League debut for the Black Cats, who on Thursday announced that this season's manager Dick Advocaat has decided to renege on a decision to retire from football, and instead sign a new one year contract at the Stadium of Light.