Michael Keane has been told to become a "boss at the back" by Everton team-mate Phil Jagielka after being left out of the England squad.
James Tarkowski, who stepped into Keane's boots at Burnley when he left for Everton in the summer, has been called up to Gareth Southgate's England squad instead.
Tarkowski: England always my ambition
James Tarkowski admits he would have found it "difficult" to represent Poland as his allegiance has always been with England.
Keane, 25, has only seven games left to convince Southgate he deserves a place in the squad for the World Cup, and Jagielka has urged his colleague to become a more commanding presence for Everton.
"He is quite a quiet lad and I have openly said, 'Shout at me, shout at someone else, no one is taking anything personally, we need to know where everyone is', and I think that is something he has in him," Jagielka told Everton's official website.
"At the start of his career here we had a few difficult periods so it was probably natural to go into your shell a little bit. But I am encouraging him to be himself and be a boss at the back - whether you are a loud person on or off the pitch, when you are on the pitch you need to pass on information."
Former Manchester United defender Keane has taken time to settle at Everton, but has started the last seven games under Sam Allardyce.
Jagielka believes Keane is now becoming a permanent fixture in the starting line-up.
"I probably had six months where I did not play much (after joining) and Leighton Baines was similar," said Jagielka. "The good thing about us back then was that it was a settled team.
"Times have changed and it is a little bit different, but not having too many changes in the team does help people settle in and, hopefully, that will be the case until the end of the season. You can see Michael's confidence is coming back, so these games will put him in good stead going forward."