Everton said the 23-year-old is set to be sidelined for around four weeks after missing the club's pre-season trips to Tanzania and the Netherlands.
Barkley's future at Goodison Park remains uncertain after manager Ronald Koeman in May said he faced being sold this summer if he did not sign a new deal.
Everton accept £75m bid for Lukaku: reports
The Dutchman last week said the situation regarding Barkley was no closer to being resolved.
Everton begin their season at home to either Slovakian side Ruzomberok or Norwegian outfit Brann on July 27 in the first leg of the Europa League third qualifying round.
They will also be without Argentina centre-back Ramiro Funes Mori after the 26-year-old had further surgery in Barcelona after tearing his meniscus while on international duty in March.
Keane joins Everton in potential club-record deal
Funes Mori will miss most of the 2017-18 campaign following a setback in his recovery and faces between six and nine months of rehabilitation.
Everton, who finished seventh in England last season, begin the new league season at home to Stoke City on August 12. AFP
COMMENTS
Comments are moderated and generally will be posted if they are on-topic and not abusive.
For more information, please see our Comments FAQ