The winger-turned-pundit believes Aaron Lennon is thriving at Goodison Park.
Lennon joined the Toffees in a permanent deal last summer after impressing in a four-month loan spell at Goodison Park last season, and has kicked on to greater success in the current campaign.
After netting twice in 14 appearances in his stint last season, the winger has scored six goals in 22 appearances in all competitions for Martinez's side in what has become the most prolific season of his career after he hit the first of those strikes in January.
The 28-year-old had fallen out of favour at White Hart Lane under Mauricio Pochettino and was left out in the cold at the start of the current campaign before moving to Merseyside, but Nevin believes Lennon has shown that Spurs' loss is very much Everton's gain.
Nevin told the club's official website: "Aaron had been in and out at Tottenham for quite a long time. We know about his pace but there was always a question mark over that final ball. But that seems to have come together at Everton.
"It may well be that there was nothing wrong with it before, he just wasn't in the right environment. This seems to suit him, working with Robbie [Martinez] seems to suit him and he's made a big difference.
"If you've got a player who can stretch teams like he does, it takes a lot of stress off of everybody else, particularly Romelu Lukaku. If you're playing up front on your own a lot of the time and nobody's running beyond you, you've only got one option. But if someone's pacy and gets beyond you, it makes your game better and easier, so it's not just what Aaron's doing himself, it's also what he's doing for the players around him."
There is no doubt that Lennon, who has won 21 caps for England, has become a crucial player for the Toffees under Martinez after the Spanish boss gave him an extended run in the side in the New Year.
The winger has been in impressive form in recent weeks, keeping other players such as Kevin Mirallas and Leon Osman out of the side.
Despite his own personal form, Lennon has not been able to do much to improve Everton's fortunes on the whole, with the club rooted in mid-table in 12th position.