The two non-roster catchers have been invited to Spring Training, primarily as insurance policies for Johnson, who underwent three surgeries during the offseason -- one on each hip and his right wrist.
The game plan is to take it easy with Johnson during the early stages of camp and see how he's doing at the midway point. If the hips and wrist are fine, he would have about three weeks to prepare for the regular season.
"I feel great and want to be behind the plate on Opening Day," Johnson said.
For the first time since 2005, Johjima will not be the Mariners' primary catcher. He walked away from the final two years of a three-year, $24 million contract extension to return to Japan.
"He was one of the best throwing catchers in the game," Wakamatsu said. "He flat-out shut down the running game. That's what we'll miss the most, but other other guys are not bad."
Injuries and lack of production, especially on offense, caused Johjima to see less action in each of the past three seasons, going from 144 games in his rookie season to 71 last season.
Johnson, 27, caught most of the games Johjima didn't, including all of the ones ace right-hander Felix Hernandez started from the late May. It was a dynamic duo as Hernandez posted a 15-2 record and 2.01 ERA with Johnson calling the pitches.
"Felix feels awfully good with [Johnson] back there," Wakamatsu said, "and it's something we would do again this year."
The Mariners were 46-29 in the games Johnson started and led all Major League catchers with a club-record 3.22 catcher's ERA.
The way Johnson handles pitchers and calls a game are his strong suits. His arm isn't as strong as Johjima's, or Moore's for that matter, but he thew out four of the eight potential basestealers in September -- despite having two bum hips.
"I feel confident in Rob Johnson and Adam Moore, and we've added some depth with [Josh] Bard and [Eliezer] Alfonzo."
-- Don Wakamatsu
Overall, Johnson nailed 29.3 percent (17-of-58) of the attempted basestealers during his first full season in the Major Leagues, considerably less than Johjima's 50 percent (19-for-38) success rate.
An improved throwing technique, and healthy body, should enable Johnson to improve his timing and accuracy.
"The surgeries on my hips will allow me to be quicker behind the plate," he said. "It has been a long time since I felt this good. I can't remember the last time I could get into my squat and not hurt."
Same goes with swinging a bat.
"It's hard to tell how much the injuries affected him, because he's a tough kid and never complained," Wakamatsu said, "but it's hard enough to hit when you are healthy, let alone having two bad hips."
"I honestly believe I can hit somewhere between .265 and .290," said Johnson, who batted .213 (55-for-258) last season, but hit .305 in 112 games with Triple-A Tacoma in 2008. "I really believe that."
Being able to use his hips properly should make a big difference.
"When you are hurt, your confidence goes down the drain," Johnson said. "It's tough asking your body to do something it can't do."
Moore, 25, goes into Spring Training competing for a spot on the 25-man roster. His progress has been so steady since being selected in the sixth round of the First-Year Player Draft in 2006, that the Mariners traded former first-round pick Jeff Clement to the Pirates last season.
Moore started the season at Double-A West Tennessee, advanced to Triple-A Tacoma, where he batted .294 with nine home runs and 43 RBIs in 91 games, and spent the final three weeks of the season with Seattle, playing in six games.
"Adam Moore proved to me that he can handle the pitching staff and defense is the top priority with our catchers," Wakamatsu said. "He showed me everything I needed to see."
The 31-year-old Bard has far more big league experience than any catcher in camp.
He spent the 2009 season with the Nationals. The switch-hitter appeared in 90 games, posting a .230 average with 18 doubles, six home runs and 31 RBI in 274 at-bats. He hit .383 in June and hit .300 with four doubles and seven RBIs in 13 Interleague games.
In his nine-year big league career, encompassing 521 games, Bard also has played for the Indians (2002-'05), Red Sox ('06) and Padres (2007-'08).
Alfonzo, originally a third baseman, was converted to catcher in 2007 and has previous Major League experience with the Cardinals, Brewers, Cubs, Marlins, Giants and Padres.
"We have good reports on both of them in handling a pitching staff," Wakamatsu said. "They also give the position the experience we didn't have [after Johjima's departure]."
Next up: Corner infielders.