Mendonca spent last season at Double-A Frisco and batted .278 with 25 home runs and 87 RBIs in 125 games and 504 at-bats. He was selected to the Texas League All-Star team. He was also a member of Team USA that won a silver medal at the Pan American Games in Mexico.
The Rangers' best catching prospects are in the lower levels of the system. They have signed Dusty Brown and Chris Robinson to Minor League contracts and acquired Luis Martinez from the Padres for Minor League pitcher Ryan Kelly. Brown and Martinez have limited Major League experience.
Jose Felix was in Major League camp last year but has not been invited this season after struggling at Double-A Frisco. The Rangers are hoping for a rebound season.
Olt is considered one of the top third-base prospects in the Minor Leagues, but with Beltre at the Major League level, the Rangers wanted to create some options for him.
"In Mike's case, I don't think there is any doubt he can play third base," Daniels said. "He is a plus defender, he has a very good arm, plus power and great makeup. We don't lose anything by moving him around. It creates options and other ways to get to the big leagues. You never know what will happen in the course of a season.
"Olt is one of the better third basemen in the Minor Leagues. Him playing first base is not a commentary on his third-base play."
Olt was at Class A Myrtle Beach and batted .267 with 14 home runs and 42 RBIs despite missing two months with a broken collarbone. He also led the Arizona Fall League in home runs, RBIs and slugging percentage this offseason.
The Rangers are also inviting pitchers Fabio Castillo, Greg Reynolds, Robbie Ross, Tanner Scheppers and Ben Snyder and infielder Greg Miclat. Pitchers and catchers report to Spring Training on Feb. 22.
This will be the third straight spring that Scheppers, the Rangers' fourth-ranked prospect
, has been in camp. The Rangers looked at him as a starter last year but now plan on using him in relief going into camp.