Jelavic, 28, has failed to score in five appearances so far this term.
Martinez said: "Niki is a top player and he's desperate to be on the pitch. But every top class player wants to be at a top class football club, and to do that you need to be able to cope with competition and high demands.
"His attitude has been a 10 out of 10 and that's why when a player comes on as a sub he makes a big difference and the team benefits.
"It's a real focus to be as good as you can as an individual, but everything comes down to the team so Niki, Arouna, and everyone who isn't starting needs to do what they can to help the team."
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