Robles has played second fiddle to Tim Howard for much of the season so far, with the Spaniard’s appearances generally being reserved for cup competition.
However, with Howard now out injured, Robles is set to be handed his Premier League chance, and Martinez believes he is ready to step up.
"Joel has been working very hard behind the scenes and waiting for his opportunity,” the Spanish boss said. “He has the support of everyone, including Tim Howard, who has been a big supporter for him.
“You need to give enormous credit to the way Joel has been working and preparing himself. [Competition] is something you want to have as a manager, you want to arrive at the training ground being able to play every player and having those options.”
Robles has made a good start at deputising for Howard, as the former Wigan Athletic stopper managed to keep a clean-sheet in Everton’s match against Newcastle United in midweek.
The Toffees ran out 3-0 winners over the Magpies to move up to 11th place in the Premier League table.
Robles’ inclusion has been welcomed by most supporters of the Merseyside club, too, due to Howard’s poor form this season.
Martinez has stuck by the experienced American, despite him making a number of high-profile errors, but Robles now has a chance to stake his claim for more regular first team action.
Everton’s next match comes against Stoke City at the Britannia Stadium on Saturday.