Lampard was visibly upset with the substitution, but Grant insisted: "Frank did well and it was not so easy after he was sick and only trained for two days.
"He played for more than 70 minutes and it was risky to allow him to play 90."
Fener striker and former Chelsea teammate Mateja Kezman said: "If Lampard goes out of the game after 76 minutes something is wrong. We are full of confidence for the second leg. We will not show as much respect for them in London."