Alcantara will draw the start at designated hitter and bat eighth in Sunday night's series finale against the Cardinals.
Alcantara will be in the starting lineup for the first time since being called up from Triple-A Iowa on May 23. The 23-year-old has gone 0-for-3 with three strikeouts and a walk over four plate appearances off the bench since his promotion, but he'll get the nod over Moises Ballesteros and Michael Conforto at DH with southpaw Matthew Liberatore on the mound for St. Louis on Sunday.