Arsenal midfielder Mesut Ozil is facing a short spell on the sidelines after damaging a shoulder.
The Gunners' £43m signing missed Sunday's 1-0 English Premier League victory over Newcastle United after being left at home nursing the injury, although he is expected to return to action early next month.
Manager Arsene Wenger said: "It is an inflamed shoulder. It should be maybe one more week, maybe less, I don't know, but not a long time."
Wenger was without both Ozil and Aaron Ramsey, who has a thigh problem, and Thomas Vermaelen and Nacho Monreal, who missed out through illness, at St James' Park. However, his side returned to the top of the table courtesy of Olivier Giroud's 65th-minute header.
Jagielka missed Sunday's 2-1 English Premier League home victory over Southampton, with the Merseyside club stating on their official website beforehand that a hamstring injury had been the reason.
And after the match, when asked about the England defender, Martinez said: "It was at the end of the game against Sunderland. 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."