But his value to Japan was underlined in his absence as they lost 2-0 to the USA in a friendly.
The Albion winger went on for the last half-hour following his 81 minutes against Mexico in California at the weekend.
He now turns focus on the away game for his club at Bournemouth, where he scored the winner last season.
Japan came in for plenty of criticism after their defeat as head coach Hajime Moriyasu changed formation and personnel.
It appears Mitoma was missed as an individual and for the way he helps make a wing-back system work and he was unable to offer any impact when he went on.
The Samurai Blue are preparing for the World Cup final next summer and their next friendly is against Diego Gomez and Paraguay in Osaka next month.
Gomez played for 74 minutes – and went off just before the only goal – as the Albirroja concluded their successful qualifying campaign with a 1-0 win away to lowly Peru.
The trans-Atlantic action for Gomez and Mitoma followed outings in the African zone of World Cup qualifying for Yankuba Minteh and Carlos Baleba.
Elsewhere in the final round of CONMEBOL fixtures, former Albion midfielder Moises Caicedo was sent off for a second yellow card 50 minutes into Ecuador’s 1-0 win over Argentina, who were playing without Lionel Messi.