The Royals selected Hill's contract from Triple-A Omaha on Tuesday.
Hill will start Tuesday's game at Wrigley Field against the Cubs, which is the same site where he made his major-league debut all the way back in June 2005. The 45-year-old put up a 5.36 ERA, 1.62 WHIP and 48:25 K:BB in 42 innings with Omaha before getting the promotion. Hill will be pitching on two days' rest after throwing two innings for Omaha on Saturday.