After that, they can be covered.
First half injuries are the worst.

I've lost many guys this year including Pacheco (4th quarter when he went out in week 2), Kenneth Walker (injured late in week 1), Cooper Kupp(injured in second quarter of week 2), and now Jordan Mason(injured in second quarter tonight).

If I hadn't lost potential points during those weeks, it wouldn't have been so bad.
I'm 4-1. My only loss was week 2, by .8 points, when I lost both Pacheco and Kupp.

I had plenty of backups ready for the following weeks.
It also helped that Walker missed only 2 games, but building a good bench helps even more.
Don't waste spots on TEs, QBs, d/sts, kickers.