The 25-year-old joined the Millers from Bournemouth until the end of the season and made an impressive start, featuring from the off in his first three games, with boss Steve Evans hinting that a permanent deal could be on the cards in the summer.
However, he missed last week's win at Tranmere through illness and had to watch Saturday's victory over Leyton Orient from the bench.
And with his replacement Claude Davis impressing and skipper Craig Morgan now back in full training following a foot injury, Addison faces a battle to get back into Evans' team.
"I just want to play every game I can for Steve Evans and for Rotherham and then at the end of the season see where we're at," he said.
"I am just concentrating on trying to be fit and play every game I can."
Addison had not played a first-team game in over a year after a serious injury at the Cherries, but he was thrown straight into a promotion race, with his new side flying high in League One.
He is ready for the challenge and believes that will help him play at a better level.
"The play-offs are a massive carrot and with the way the squad has improved, even since I have come here with the signings that we have made, then everyone's game is going to raise," he added.
"People putting pressure on me will help me raise my game."
Source PA