The Northern Ireland international returned from a two-month ankle injury lay-off to make a game-changing substitute appearance in Albion's 1-0 triumph over Chelsea four weeks ago - but has since struggled with tonsillitis.
"My own form this season hasn't been as good as it could have been and I will be the first to hold my hand up and say that," Brunt told the WBA website.
"Fitness-wise, I am still a little way off where I need to be but that will come through training and playing games.
"But if I am picked to do a job, hopefully I am doing what the gaffer wants me to do and that's why I'm playing.
"There are a lot of boys in the squad capable of doing everybody else's jobs so you've got to stay on your toes, especially in the last few games."