Ravin was on the lineup card earlier in the day, but the move was officially announced about 30 minutes before the first pitch of Saturday's game.
Ravin has a 6.43 ERA in seven appearances this season with the Dodgers and had allowed four runs in his last 1 2/3 innings with the club.
West has yet to make an appearance with the Dodgers in the Majors but appeared in three games with Texas last season.
Steve Bourbon is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.