Barkley's superb winner against Swansea at the Liberty Stadium on Sunday has increased speculation that some of the top clubs will make a bid to sign the England midfielder in the January transfer window.
But the Everton boss, who has described the 20-year-old as "a diamond", is determined to keep his prize asset at Goodison Park.
Martinez told the Daily Mirror: "Even if we got a Gareth Bale size valuation we would never even consider it in January.
"Ross is an icon for us. He represents everything we are trying to do this season, so even if a stupid offer arrived in January it would never affect us.
"It is important for us as a football club to show we are making the right decisions.
"There is no question mark over Ross's future, he is in the best moment of his time and is everything we want a player to represent at Everton.
"There is not even a question mark against whether he is going to be here in February or not."
For those who don't seem to understand what Martinez is implying I'll clarify...he isn't saying that Barkley is worth 85 million, he's merely stating that they aren't looking to or certainly don't want to sell him as whats the point in blooding young players only to sell them on as soon as they hit form which is a good principle to have in my opinion.- m4rr15