Everton have announced they have completed the signing of winger Christian Atsu on a season-long loan from Chelsea.
Martinez identified Atsu as the man to fill the gap left by Gerard Deulofeu's return to Barcelona after a successful loan stint last season.
Negotiations had not been straightforward, however, with Chelsea reportedly wanting assurances that the 22-year-old Ghana international would get regular first-team football at Goodison Park.
Martinez indicated last week that progress was slow, but was always hopeful that Atsu would be a part of his squad in time for Saturday's opening Premier League fixture at newly promoted Leicester City.
"I'm very happy to be joining Everton because it's a great club, which likes to play football, and it's a great pleasure to be here," Atsu told the club's official website. "Playing in the Premier League has always been a dream for me and I have achieved that dream.
"This is the biggest level for me to play at. I know that it's a very competitive league and I believe with hard work we're going to be successful this season."
Roberto Martinez added: "He's a player who fits in with the culture and the way we want to play. He's a very gifted technical footballer and he's got the right personality and character to fit in with the group, which is vital.
"He will excite fans because he brings something completely different and a different way of playing to what we've got in the squad. He's a left-footed player who loves taking people on and he's got a really good understanding of the game for such a young man.
"He also brings extra competition in a position in which we felt we needed a player full of desire and hunger, who really wants to make things happen in the final third of the pitch."
Atsu, who has yet to play a competitive senior match for Chelsea since arriving from Porto in 2013, spent last season on loan at Dutch club Vitesse Arnhem, with whom the Londoners have close links.
He made 28 league appearances for them last season, scoring five goals as they finished sixth in the Dutch Eredivisie.
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