Lallana was substituted at halftime, with Martin saying the decision was precautionary.
(It's) nothing serious but he just felt his groin a little bit so we'll assess that," he said.
"He's been massive for us with the way he takes the ball and is so brave. He's a beautiful footballer to watch and he gave some brilliant moments today.
"He couldn't continue so it was disappointing. The subs impacted the game and that's all you can ask for I think.
"At times of season, I've made subs that perhaps, when you look at it with hindsight, which is a beautiful thing, I could have made them a bit later.
"I'd already had that in mind and I should have changed that. Today they had a brilliant impact. Yuki (Sugawara) got an assist and looked fresh.
"Tyler (Dibling) was great when he came on and then Lesley (Ugochukwu) and Paul (Onuachu) helped to shore it up.
"Joe Aribo had some tough moments today but what he gives us out of possession and his willingness to still take the ball is huge."