The Reds drew 1-1 with the Gunners, as Bruno Fernandes's free-kick was levelled by Declan Rice's strike, and Martinez, out for the season with a knee injury, watched on as Ruben Amorim's side came agonisingly close to taking all three points.
Speaking to MUTV after the game, Eriksen said: "We see him often at the training ground obviously, so he's still one of the boys.
"And we know what he's going through with his rehab, and a few other guys.
"Anyone who comes and supports the games is a good sign. And, yeah, we're just waiting for everyone to come back really."