Wanted to Ask you guys (Part 2)

I just tweaked my back at the gym yesterday and on t-day I had an all-out feast (binge you could call it) and competing may be a possibility for me within the next year (ya it's quite a while) but am quite curious about how my current routine can affect me.

The past few months I have been having like 1 day on, 2 days off, 2 days on (lifting that is) and there has not been a set schedule for the days I lift. If I feel like I want a day off, I take it off. But I usually didn't go past 2 days off. Now I had just injured my back and already took 2 days off before the day I hurt my back and now I can't do the leg days that I have in my program. I could maybe do arms but I want to resume where I left off when my back heals up.

Am I going to lose any muscle mass at all with all these rest days? Was the amount of rest days I was doing before too much? How should I handle this situation?

Edit: Or can I do my workout and sub these exercises;

Front Squats
RDLs
Overhead Squats

with others?