Montero, 23, has hit .293 with one home run and 13 RBIs in 21 games for Lara while playing mostly first base and designated hitter. The Mariners are converting him from catcher after he struggled behind the plate last season before being sent down to Triple-A, and then being suspended the last 50 games in the Biogenesis case.
"He's trying to get some at-bats that he missed during the year," Gwynn said. "He'd been hitting the ball better as he got going down there, so we're happy about that."
Montero only played 16 games at first base for Triple-A Tacoma due to a knee injury and then his suspension, so he's gaining some valuable experience at that position after coming to the Mariners as a catcher in the Michael Pineda trade two years ago.
"I know he's working extremely hard for somebody that just started playing there," Gwynn said. "I can guarantee he's taking a lot of ground balls. He's a willing worker."
The Mariners are also getting some extra winter work for right-hander Erasmo Ramirez, who was outstanding in his debut for Lara last Saturday. Ramirez, who went 5-3 with a 4.98 ERA in 14 games for Seattle last season, threw five shutout innings, allowing no hits, against Caracas.
Ramirez had one walk and six strikeouts while throwing 53 pitches in a game Lara eventually lost, 6-1, after Caracas rallied against the bullpen. But it was a strong showing for the 23-year-old, who missed the first three months of last season with elbow problems.
"It was a lights-out performance," Gwynn said. "I think we're looking to give him maybe five starts and shut him down around Dec. 15 to get ready for spring. He missed some innings last year, so we just want to get him ready to go again. I don't know our exact plans on where he'll pitch next year, but I know he's a big league pitcher."
The Mariners also have several young position prospects playing in the Venezuelan League. Shortstop Gabriel Noriega, who spent last season with Double-A Jackson, has hit .233 with seven RBIs in 29 games for Lara, while catcher Jesus Sucre has hit .176 in 11 games for Caracas.