Everton manager Roberto Martinez believes that Ross Barkley's "level of ability" is one of the best in European football, and insists that the midfielder is used to dealing with criticism.

The 21-year-old, who has suffered injury woes this season, has failed to match the form that earned him a call-up to England's World Cup squad last year.

However, last week, Barkley impressed during spells off the bench in England's Euro 2016 qualifier against Lithuania and friendly with Italy.

"He is used to having to deal with extremes," Martinez said in this morning's press conference. "When he is playing well he's called the best footballer in England, but when he has a bad game, it changes. What is true is that he has an incredible level of maturity.

"He's learned a lot having come through a serious injury and it doesn't surprise me that he made a good impact coming off the bench in both England's games. I think he is a better player for that experience of the injury.

"Ross is one who takes responsibility in big moments of games and has developed that physicality as well. There are not many footballers in Europe with the same level of ability."

Barkley is expected to play a part in Everton's Premier League match against Southampton on Saturday.