Roberto Martínez has promised a "frustrated" Gerard Deulofeu that he will make his competitive debut for Everton in the Capital One Cup but admits it could be 2014 before Goodison Park witnesses the best of the Barcelona recruit.

The Everton manager signed the 19-year-old on loan from the Spanish champions but has yet to deploy the winger in the Premier League this season. Martínez insists Deulofeu, who scored 18 goals for Barcelona B last season, needs time to adapt to British football but will feature at some stage in the second-round home tie against Stevenage on Wednesday.

"He's been frustrated so far, which I really like," the Everton manager said. "For someone so young to feel they want to help the team is something you want to see as a manager. We need to be patient with Gerard. We will see the best of him in January or February. He's an exciting winger. He takes people on and can play on both wings.

"He is the sort of player who can create something out of nothing but you need to remember that he is still very young and growing physically. It is also a big change from the way he [was] playing [at] Barcelona to adapting to the British game. It's going to take a little bit of time but straight away you can see he's got something that we haven't got in the squad. He will be really important for us throughout the season. I have seen many crowd pleasers who do not have an end product and are not effective for the team. Gerard is a crowd pleaser with an end product."

Everton beat several Premier League and European clubs to the season-long loan for Deulofeu but Martínez insists his style of play, more than his Spanish contacts, was instrumental in the deal with Barcelona.

He added: "It was a great compliment towards Everton because he had four, five, maybe more options. Barcelona think Gerard will be a top player who will be an important player for their first team and for them it was a question of how to bridge that gap in his development.

"For him, the biggest difference is going from a team like Barcelona who normally get so much respect that they give you 75% to 80% of possession. For a winger it is different when you play in a league which is more open and more box to box. That's part of the adaptation for Gerard and it is nothing he can't achieve."

Martínez confirmed there have been no more bids from Manchester United for Marouane Fellaini and Leighton Baines since a £28m joint offer was rejected 11 days ago, although another move for the Belgium midfielder is anticipated. Should Fellaini go, Martínez would be interested in a reunion with the Wigan midfielder James McCarthy. "I signed him young and have huge admiration so it doesn't take much to make that story," said the former Wigan manager. "But there has been no bid."