According to Jeff Passan of Yahoo Sports, the Astros have signed top first base prospect Jonathan Singleton to a five-year contract with three club options. The historic deal -- a first for a player with zero major league service time -- carries $10 million in guaranteed money and can be worth up to $35 million if all the options and incentives are triggered. Singleton, 22, will be promoted from Triple-A Oklahoma City before Tuesday's game against the Angels to take over as Houston's regular first baseman. He was sporting a .941 OPS, 14 home runs, and 43 RBI in 54 games this year at Triple-A and should be owned in all mixed fantasy leagues.