The youngster has been in impressive form for Everton this season.
The young midfielder is enjoying a fine campaign so far for Roberto Martinez’s team, having established himself as one of their star men.
He has now been involved in 20 goals in all competitions this season, the latest of which was the opener in the 2-0 win over Bournemouth in the FA Cup.
That is a drastic upturn in his performance levels from last season in what was a difficult campaign for him and his club.
And Shearer says that improvement has come about from him believing in himself more.
“I think this is the difference in his game from last season, he believes in himself more,” he told Match of the Day.
“He believes that he’s got to have more efforts at goal. If you keep having enough, you might get a bit of luck, and that’s what he got [against Bournemouth].”
Barkley will now be hoping that he can continue his fine form until the end of the season and with England at Euro 2016.
The midfielder is certain to be selected by manager Roy Hodgson given how he has impressed this season.
There is competition for his preferred number 10 spot though, with Tottenham Hotspur’s Dele Alli also starring this season.
Who is first choice could be determined by whichever player has the greater impact in the games remaining this season.