The England international has been heavily linked with a switch to Manchester United, with former Toffees coach David Moyes having taken charge at Old Trafford.
The Scot has made obtaining the attack-minded defender one of his top priorities, and the Merseyside club may find it hard to persuade their star man to stay put.
If Baines does elect to move on however, Martinez has lined up Siqueira as the man to fill the left-back void.
Reports suggest that negotiations are at an early stage, but Everton are very keen to secure a deal.
The 27-year-old has been impressive since his 2010 move to Spain –initially on loan – from Udinese.
Although he only penned a new contract in 2011, the defender has made it clear that he would jump at the chance to move to a big club.
As a result, Granada are said to be willing to do business for a fee in the region of £4.5m, which would leave Everton with plenty of spare change should Baines leave for United.
Galatasaray are also interested in the Brazilian, but playing in the Premier League could be a decisive factor.
Everton fans, could Guilherme Siqueira be the ideal replacement for Leighton Baines? Or should your side do all they can to keep hold of their man?
Join the debate below!
[cat_link cat=”everton” type=”grid”]