Martinez, 25, tore cruciate ligaments in Wednesday's SuperCup defeat by Borussia Dormtund and has been ruled out until at least the end of the year by the German champions, though Spanish media claim it could be as long as seven months.

"We definitely need a new player," said Guardiola, who achieved the domestic double in his first season in charge but fell short of defending the Champions League crown won under predecessor Jupp Heynckes.

Guardiola, who also revealed that German World Cup-winning midfielder Bastia Schweinsteiger would be absent for some time with a tendon injury, refused to give names, only saying he was looking for a young player.

"He must be big, quick, good in the air, capable of playing in different positions and not be expensive," he said.

"But for that it is perhaps already a little late."

According to media rumours, among those on Guardiola's list who figure are Spanish champions Atletico Madrid's Uruguayan defender Diego Godin and defensive midfielder Sami Khedira, who is at Real Madrid, and Bayer Leverkusen's Gonzalo Castro -- although none could be described as young in terms of footballers as they are 27 or older.