The St. Louis Cardinals on Friday purchased the contract of Class AAA Memphis infielder Ryan Jackson.

Jackson, 24, replaces infielder Tyler Greene, who was traded to the Houston Astros on Thursday for a player to be named later or cash.

Jackson will wear No. 8 and will be available when the Cardinals play Friday night in Philadelphia. He was not on the 40-man roster, making it necessary for the Cardinals to purchase his contract.

A fifth-round pick (159th overall) from the University of Miami in the 2009 draft, Jackson was batting .269 with 23 doubles, 10 home runs, 45 RBIs and a .331 on-base percentage at Memphis in 113 games. He has played primarily at shortstop, although he also has been used at second base.

Jackson will become the eighth player to make his major-league debut for the Cardinals this season, joining Matt Adams, Chuckie Fick, Sam Freeman, Joe Kelly, Barrett Browing, Erik Komatsu and Trevor Rosenthal. Kelly and Browning are the only ones still on the major-league roster.

Jackson was a college teammate of Cardinals center fielder Jon Jay and was a member of the 2008 Team USA national team. Baseball America in 2011 tabbed Jackson as the best defensive infielder in the Cardinals system.

With veteran Rafael Furcal battling a sore back, Jackson provides insurance at shortstop. Furcal received a cortisone injection this week, but typically, the benefits of the shot wear off after about two weeks.

Furcal has slumped in recent weeks, and he began Friday hitting .265 with a .334 on-base percentage. Furcal will bat eighth against the Phillies on Friday, with Jay being used as the leadoff hitter for the third consecutive game.