ARLINGTON, Texas - The Texas Rangers have selected the contracts of four top prospects from their minor league system to protect them from next month's winter meetings draft.

Texas on Thursday night added to its 40-man roster right-hander Luke Jackson from Triple-A Round Rock, and infielder Hanser Alberto, catcher Jorge Alfaro and right-hander Jerad Eickhoff from Double-A Frisco.

To make room on the roster, the Rangers designated outfielder/first baseman Jim Adduci for assignment, traded outfielder Daniel Robertson to the Los Angeles Angels for a player to be named later or cash, and placed right-hander Miles Mikolas and left-hander Aaron Poredo on unconditional release waivers for the purpose of both playing in Asia next year.

Among the prospects added to the 40-man roster, Alberto won a Gold Glove as the top defensive shortstop in the minors last season. Eickhoff led all Double-A pitchers and Texas minor leaguers with 144 strikeouts for Double-A Frisco, while Jackson was 9-5 with 126 strikeouts in 123 1-3 innings combined for Triple-A Round Rock and Frisco.

Earlier Thursday, the Rangers signed catcher Chris Gimenez and right-hander David Martinez to minor league contracts with invitations to major league spring training. Left-hander Efrain Nieves was signed to a minor league deal.

Gimenez was on the Rangers' opening day roster last season after being acquired on a waiver claim from Oakland in late March, then was traded to Cleveland in August. The catcher combined to hit .241 with 11 RBIs in 42 games for the Rangers and Indians last season.

Martinez had a 6.38 ERA in seven relief appearances for the Houston Astros the past two seasons. He went 5-6 with a 5.64 ERA and started in 13 of his 22 appearances for Triple-A Oklahoma City last season.