But aside from Hart and switch-hitting first baseman Justin Smoak, the only sure right-handed option in the lineup at this point is catcher Mike Zunino. Which is why rather than an afterthought when it comes to offense, the 23-year-old backstop could loom large as he develops both at the plate and behind it.
"I think he's going to be big for us," manager Lloyd McClendon said Wednesday. "I don't see this young man as an automatic out, so to speak. I think he has some unique qualities from an offensive standpoint. He's got some juice. He can hit the ball with power to all fields. He's been fast-tracked to the big leagues, but I don't think he's going to be overmatched by any means."
When Zunino was called up midseason last year, he was thrown immediately into the starting lineup and a situation where his first priority had to be learning a new pitching staff as well as opposing hitters in on-the-job training at the Major League level.
That is a sink-or-swim scenario for any catcher, let alone a kid with less than 100 games of Minor League experience. Zunino held his own behind the plate, drawing rave reviews for his ability to work with pitchers and play defense as a raw rookie.
But the bat wasn't there yet and the youngster put up a .214/.290/.329 line in 173 at-bats over 52 games.
There's a lot more there, however, from the 2012 first-round Draft choice. And the Mariners are hoping to tap that potential this year, with hitting coach Howard Johnson and McClendon already pleased with Zunino's progress after a slight adjustment in moving his hands back at the start of his swing.
Early results are encouraging. Zunino laced two doubles in Tuesday's 4-1 win over the Dodgers, giving him four hits -- including three doubles -- in his first seven at-bats this spring.
"He's been working on his trigger all spring and it just goes to show you what kind of talent he has," McClendon said. "I think he's in the process of putting it all together and he should be an enjoyable young man to watch this summer."
Zunino hit five doubles and five home runs in 173 at-bats during the regular season last year in a second half interrupted by a five-week stint on the disabled list with a broken hamate bone in his left hand. That injury didn't help matters, but Zunino had a full offseason to work on things and then his early-camp adjustment has only fueled a feeling that the youngster could be ready to take a step forward offensively.
The 6-foot-2, 220-pounder has plenty of power, which he's consistently displayed during batting practices this spring. But his key in games figures to be learning to take what pitchers give him and drive the ball to all fields, as he showed Tuesday by smoking one of his doubles the opposite way to right-center.
"I'm just recognizing good pitches that I can hit and not trying to do too much with them," Zunino said. "I was able to take a ball to the right-center gap [Tuesday] and that's probably what I should have done with it. I didn't try to do too much. I think when I'm seeing the ball well, that's where my strength should be."
As for his new hand position in his stance? Zunino says it's already becoming second nature.
"It's just having your hands and body in a completely loaded position," he said. "I wasn't quite getting all the way back there when I first got in camp and even last year. So I think just being able to get my hands all the way back is allowing me to free up my swing a little bit and it gives me more time to recognize pitches.
"I can feel it now. I have a couple things to kind of remind me to get to that spot. I've tried to do a lot in the cage and a lot in batting practice, so when it comes to a game, instead of thinking I have to apply my approach to my at-bats, I just go with it."
It's early, obviously, and Zunino figures to see a lot more offspeed pitches and be attacked in different ways once the real games begin. But there's nothing like hitting well right out of the gate to build confidence and reinforce the changes being made.
For both the Mariners and Zunino, those sweet swings could play large this year.
"It's nice to be able to see results," Zunino said. "I just want to keep having good at-bats and my goal this year is I don't want to give at-bats away. I want to work counts and be able to hit balls hard and just do whatever I can in certain situations. That's what I'm going to try to work on all spring."