Swelling from a sprained joint is a one way street. Once it starts, you have to rest it until it goes down.
Bryant Young continued to play in the Air Force game in 1991, after he got chop blocked in the knee (got sprained). He was out for the bulk of USC and Navy, and mostly out for the Tennessee game later, and we really could have used him.
That being said, Moore is probably being treated with lots of ice, compression, and anti-inflammatory meds right now.