The former Bafana Bafana skipper lasted only 10 minutes of last Saturday's 2-2 draw with Arsenal before picking up a groin problem, while Belgian striker Lukaku, who moved to Goodison Park from Chelsea on a permanent basis this season, hurt a toe.
"They have both been assessed," Martinez said yesterday.
"Stevie P is going to miss the game at the weekend. He is the one that is going to take a little bit of time. Stevie is going to be out and he is going to join Arouna Kone and Bryan Oviedo, who are the only other two players that are not available.
"Romelu, we will keep assessing him. He has reacted well in the 48 hours after the game. At the moment it is too early to know if he will be available at the weekend but I am quite positive with Rom."
Gibson missed much of last season after hurting his knee but is back to full fitness.