Also making the jump is former Phils bullpen and catching coach Mick Billmeyer, who's expected to fill the bullpen coach role in Detroit.
The Tigers have not yet announced the additions. Ausmus did not respond to a text message for comment.
Like Detroit this past season, Philadelphia used two hitting coaches, with Joyner supporting top hitting coach Steve Henderson. Joyner received a good share of credit in Philly for the emergence of Domonic Brown, who grew up from perennial prospect status to legitimate Major League hitter in 2013. Brown hit .272 with 27 home runs and 83 RBIs.
Joyner has been in the top job before, serving as Padres hitting coach from July 2007 to September 2008. After stepping down from the job, he spent four years as the lead hitting instructor for Major League Baseball's international elite-level development programs, coaching players in Italy, Brazil and the Netherlands.
Ausmus didn't join the front office in San Diego until after Joyner left, but they were teammates with the Padres in 1996. Joyner's playing career was his claim to fame, including a 22-homer, 100-RBI rookie season with the Angels in 1986.
For his 16-year Major League career, Joyner batted .289 with 204 home runs and 1,106 RBIs.
Joyner was seeking a hitting coach position a month ago, turning down an offer to return to the Phillies on Ryne Sandberg's staff in order to pursue other opportunities. A week later, he changed his mind and accepted the Phils' offer.
Billmeyer spent four seasons as Philadelphia's bullpen coach before becoming a catching coach this past season. He was the Phillies' catching instructor for five years before that. As bullpen coaches go, he has a fairly extensive resume.
Two openings are left to be filled on the Tigers' staff. One is a first-base and infield coach, the role Rafael Belliard filled this past season on Jim Leyland's staff. The other will be an assistant hitting coach if Ausmus chooses to have one, or another coaching position if not.
Jason Beck is a reporter for MLB.com. Read Beck's Blog and follow him on Twitter @beckjason. This story was not subject to the approval of Major League Baseball or its clubs.