He wrote in the Sun on Sunday: "Last season, people thought Martinez was crazy to turn down Aston Villa to stay with Wigan.
"It turned out to be a good call. Alex McLeish went instead and has since been sacked.
"While his stock has slumped, Martinez's is enhanced after another year of keeping Wigan in the Premier League.
"Now is the time for the Spaniard to go and if I were him I'd jump at the chance to go to Liverpool.
"It might not be the best time in the club's history but it's still a great job. Put it this way, I'd take it and my mobile is on!"