Kermorgant made his first start in six weeks in Sunday's goalless draw with Wigan, but suffered a recurrence of an ankle injury and could face another spell out.
The French striker still has three goals to his name despite an injury-hit campaign so far and Pritchard admits the Addicks miss his presence in attack.
"He's disappointed and frustrated, he wants to play and sometimes he pushes himself too far," said midfielder Pritchard.
"He's moody anyway - if he scores two goals, he's upset he hasn't scored a hat-trick.
"But he's been looking good in training and for that to happen is frustrating for the whole team, he's our talisman and we look to play off him so when he goes off it is a blow.
"He is important to us, he's the spirit of our team. He's so good in the air and it's a quality we miss.
"It's about keeping his head up and his spirits high, and hopefully it's not too bad."