The Everton center back could be sidelined throughout January with a hamstring injury picked up over the festive period, though his manager is hopeful of an early comeback.
The England center back suffered soft tissue damage to his hamstring during his side’s 1-0 defeat to Sunderland on Boxing Day. As a result, Jagielka missed Sunday's 2-1 victory over Southampton, with Antolin Alcaraz deputizing in the Everton back line alongside Sylvain Distin.
After the game, Martinez said: "With this soft tissue injury it could be up to four weeks, but knowing Jags he will be back earlier. It is just the accumulation of games and the demands of this month – November into December is high-risk in terms of injuries to the players. When you have the number of games we play, it is understandable."
Until his recent injury, Jagielka had been ever-present for his side throughout the current league campaign, and will be hopeful of his good form for Martinez's new-look side earning him a place in the England national squad for the summer's World Cup.