Water damage

Hello fellow home owners,

I’ve noticed recently that water stays accumulated near garage door closure where it meets the concrete floor. There is a two by four vertical stud where the tracks and rollers are connected to (common garage build). After it rains, water stays stuck at the bottom where the concrete and the wood meet and you can see it’s been chipping away. Any ideas what I can do to “fix” or prevent anymore water damage? Home state is Arizona so it’s only during the summer season that we can massive downpours but the rest of year is pretty dry. Any suggestion(s) helps!