Guilherme Siqueira
Everton line up a deal for Siqueira should United return with improved Baines bid. (Reuters)

Everton have a verbal agreement in place to sign Granada full back Guilherme Siqueira should Manchester United return with an improved offer for Leighton Baines.

Roberto Martinez has identified the Brazilian-born defender as his ideal replacement should the influential Baines leave Goodison Park this summer, the Daily Mail report, and is ready to ratify a £4m move that will see the defender move to the Premier League.

But a deal will only be sanctioned should David Moyes and United return to the club with an improved bid for England international Baines, after the Toffees rejected a bid of £12m at the beginning of the month, with a bid in the region of £20m seen as a more reasonable price.

The 27-year-old, who has also attracted the interested of Swansea City, helped Granada survive relegation back to the Segunda division last campaign, seemingly doing enough to convince former Wigan manager Martinez that he is capable of filling Baines' boots.

The Mail also suggest Siqueira's representatives have already met with Everton officials ahead of a proposed move to the blue half of Merseyside where he would become the fifth arrival at Goodison Park this summer, following the signings of former Wigan trio Arouna Kone, Antolin Alcaraz and Joel Robles and Barcelona loanee Gerard Deulofeu.

The developments in Everton's pursuit of the full back provide a strong indication that United could be prepared to increase their offer for Baines. Despite Everton owner Bill Kenwright remaining hopeful of the left back's continued stay at Goodison, the opportunity to work with former manager Moyes and play for the Premier League champions could prove to be too enticing for the 28-year-old.

Although United may be reluctant to meet Everton's £20m asking price for a defender who would ultimately have little resale value, the club's newly appointed chief executive Ed Woodward recently declared the club are willing to match Moyes' ambition in the transfer market, whoever the Scot chooses to target.

"We haven't got money burning a hole in our pocket but we have got a strategy on player purchases and if David wants to go after a stellar player he can do that," Woodward was quoted as saying on Sunday.

"The way we worked with Alex (Ferguson) was that he would identify the transfer targets and take them to Joel (Glazer) and (former chief executive) David Gill, who would have discussions which ended with them backing him in the transfer market every single time and we see that continuing with David Moyes."