Moyes must come up with a formula to beat Leicester, and move to within a point of the third-placed Foxes, at the London Stadium on Sunday.
"We were always aware that we could run into a situation like this," said Moyes.
"Up until now it has worked very well, we've been in a good position with it. We'll try and keep it going. We will have to look to see how it works.
"There's a lot of talk of playing with false nines nowadays. Manchester City, probably the team who can most afford to do it, chose to play with false nines and it's not done them too much damage.
"It can happen during a season, you can lose your forwards or defenders but hopefully we'll have enough options to keep everybody guessing about how we're going to play."