The Cardinals added four prospects to their 40-man roster on Friday, protecting them from being selected in the upcoming Rule 5 Draft.
The Cards purchased the contracts of outfielder Magneuris Sierra, infielders Eliezer Alvarez and Edmundo Sosa and right-handed reliever Rowan Wick. In clearing space for those four players, the Cardinals lost left-hander Tim Cooney to the Indians on waivers.
The Cardinals' 40-man roster is full.
St. Louis previously dropped Mitch Harris, Alberto Rosario and Mike Ohlman off its roster in October, then designated Dean Kiekhefer and Jeremy Hazelbaker for assignment earlier this month. Both were claimed on waivers.
Sierra, the Cards' No. 6 prospect according to MLBPipeline.com, was an obvious selection. The 20-year-old future center fielder hit .307/.335/.395 with 31 steals for Class A Peoria this year. Signed out of the Dominican Republic in 2012, Sierra was named the Cardinals' Minor League Player of the Year in 2014.

Alvarez and Sosa were Peoria's double-play tandem up the middle, earning Midwest League All-Star nods along with Sierra. Alvarez, 22, hit .323/.404/.476 with 36 steals in 116 games. Sosa, 20, hit .270/.307/.343 on the year. He is the Cards' No. 7 prospect, per MLBPipeline.com.
Wick, a 24-year-old former catcher who moved to the mound last year, went 2-0 with a 2.44 ERA in 44 1/3 innings over 44 appearances for Class A Advanced Palm Beach and Double-A Springfield. Wick struck out 57 batters and held opponents to a .186 average while allowing only one home run.
Those additions came at a price, as the Cards moved Cooney off their roster and couldn't get him through waivers. Cooney, 25, was the Cards' No. 18 prospect but didn't pitch this year due to shoulder issues. He posted a 3.16 ERA over six starts for the Cards in 2015.
Among those left unprotected heading into the Rule 5 Draft, which will be held Dec. 8, was No. 20 prospect Allen Cordoba, a 20-year-old shortstop who hit .362/.427/.495 in 50 games this year but has yet to play for a full season.
In addition to those moves, the Cards signed a handful of players to Minor League contracts that include invitations to Major League Spring Training: first baseman/outfielder Chad Huffman, outfielder Todd Cunningham, infielder Wilfredo Tovar, left-handed pitcher Zach Phillips and right-hander pitcher Kendry Flores.

Huffman, 31, batted .286 with an .892 for Triple-A Toledo last season after spending two years in Japan. Cunningham, 27, hit .148 in 20 games for the Angels. Tovar is a 25-year-old middle infielder who hit .249 and stole 29 bases for Triple-A Rochester this year.
Phillips, 30, made a brief cameo for the Pirates this year, posting a 2.70 ERA and 1.35 WHIP in eight appearances. Flores, who turns 25 next week, spent most of this year with Triple-A New Orleans, where he recorded a 4.53 ERA, but he posted a 2.29 ERA in 21 starts over three levels in the Marlins' system in 2015.