Ramirez, who arrived in the Austin, Texas, area on Thursday and started working out with Round Rock on Friday, will be in the lineup as the designated hitter.
The Rangers have not set a number on how many games Ramirez will play for the Express. They were scheduled to meet Ramirez on Friday to go over their plans for him. General manager Jon Daniels has said that Ramirez will have to earn the club's consideration before bringing him up to the major league level.
Ramirez will play for a prorated salary at the league minimum if he makes it to the Rangers. He has said he'll donate the money to charity and his church.
Ramirez batted .352 with 8 home runs, 13 doubles and 43 RBIs for Taiwan's EDA Rhinos of the Chinese Professional Baseball League. Ramirez was removed from the Rhinos' active roster on June 19.