"It's been a tough couple weeks not being able to be involved in training or at the games, as it's times like this that everyone is pulling together as a team and being involved is really important," Niemi told the club's official website.
"I've been there in spirit though and, prior to Saturday's result, there was a real buzz around the training ground and we need to keep that going.
"I injured my Achilles and have been receiving treatment which has kept me out of the squad but Kasey has done a great job, so I'm just going to focus on coming back and training hard and then see what the boss decides.
"Whatever happens, it's really important that we stick together and treat every game like a cup final between now and the end of the season.
"I've been in a relegation battle before with Southampton which ended up in the worst possible way and it's not a feeling I want to repeat and not one that anyone wants to see at Fulham."