Stones was left out of the Everton starting lineup for a few matches for making mistakes.
The England international defender has now regained his place in the Toffees’ team, but former Everton striker Gray believes that the damage has already been done.
“Everyone keeps telling me that this is the best group of players they have had since my day in the eighties when Everton were winning things,” the former Scotland international wrote on Sport360.com.
“Well, let me tell you, if that’s true and if they have got the talent – which for me they clearly have – then it’s up to the coach to bring out the best in them and get them playing in a way that brings success and he has failed to do that.
“They have won only four home league games this season and with this group of players that is just not good enough. I think he has lost John Stones because of the way he has treated him this season and maybe one or two other players.”
It is Gray’s opinion that Martinez has “lost” Stones, as there has been nothing in the 21-year-old defender’s performances in recent matches to suggest that his relationship with the Everton boss has been damaged.
Perhaps Martinez should have dealt differently with the English youngster when he was going through a bad spell, but it is within the Spaniard’s right to do what he wants to regarding team selection.
Stones has created four chances in 29 Premier League appearances for Everton so far this season.
The former Barnsley youngster has a pass accuracy of 89% and a shot accuracy of 14%, and has won 46 headers, 21 dribbles and 34 tackles.