Martin returned to pre-season training with a short-term deal to his name and a far from certain future at Gresty Road.
Davies believed the 23-year-old former Scotland Under-21 international had grown too comfortable in the role of understudy to Steve Phillips.
But renewed hunger and Phillips' recuperation from knee surgery opened the door for Martin to establish himself as the Railwaymen's number one
"He's really reacted to what we said in the summer," said Davis after rewarding Martin for an ever-present season to date in League One with a fresh 18-month deal this week.
"We felt that he was under-achieving as a player. We'd seen the talent but he was content with sitting around and not challenging Steve enough.
"So we just threw that gauntlet out to him, he came back fit and raring and he's actually shown us what he can do.
"You're not an Under-21 Scotland international for nothing. If you're in and around their thoughts then you've got to be a decent keeper.
"But he hadn't produced it, he hadn't played the games. It was about him playing some games, building his career again and realising that he's not a bad goalkeeper.
"Myself and Neil saw the ability, it was just trying to get that out of him. I think what we did in the summer has made him realise he can be a good keeper."