"I've been to have scans and X-rays on my back and I'm hoping that it's not going to be too serious," Purse told icons.com.
"I have been struggling for the last couple of days. It happened quite innocuously really, there was no-one within five yards of me, and when I jumped to get the ball, it went over me and I collapsed to the floor in agony. I didn't feel anything pop, it felt like someone was sticking a knife in my back.
"As soon as the physio took one look at me I was taken off. It was a nightmare, but it's just one of those things. It still doesn't feel great now, although I don't think it will be anything too major and hopefully I'll play this weekend.
"It will be a late decision. There isn't a great deal I can do. I went to the chiropractor on Tuesday and he got rid of a few crunches and cracks, so all I can do is rest up now.
"The Leicester game was meant to be on Tuesday, but they have rearranged the game. I wish it was still on Tuesday, as I'd have more time to recover then.
"But I'll still be going along, whether I am fit or not, to cheer the lads on. We need to build on last Saturday's result and hopefully, I'll be given the all-clear and can play my part."