But despite the difference in experience behind the plate, both are getting the same amount of attention in Cubs camp this spring. They're two of seven catchers in camp and cramming a lot into their days.
"It doesn't matter who you are, you get the same reps," said Lalli, 28, who signed with the Cubs as a non-drafted free agent in 2006. "I just think the theme of camp is you're going to work hard, no matter who you are, and see where it gets you."
Brenly, a 36th-round pick in the 2008 Draft, is the son of Cubs television broadcaster Bob Brenly. How important is baseball to the Brenly family? When they moved into a new house, they installed a batting cage before buying a kitchen table.
"The cage was up and ready to go before everything else was ready to go in the house," Michael said.
When Lalli signed with the team, it was as a catcher. At that point, he had only used a catcher's mitt when tested in front of scouts.
"I had never caught before," he said. "Up until last year, I'd probably only caught 30, 40 games lifetime. Last year, I caught maybe 50 or something. I'm trying to build on that."
He did well enough to make the Southern League All-Star team last season as a catcher. A left-handed hitter, he has a career .303 average in the Minor Leagues.
"I played third base in college and some first," Lalli said. "I just kind of thought my fit was a left-handed bat behind the plate and see if I can catch on back there. I think I have, now that I'm getting the reps and stuff. I feel great, I feel like a catcher."
The Cubs have been successful converting other players to catcher, such as Steve Clevenger, a former shortstop who has a chance at the backup job on the big league team.
"I definitely feel I can help a team that way or any way," Lalli said. "I have the ability to bounce out to a corner. I'm just trying to build on last year. Last year was really the first year that I consider that I caught. In previous years, I'd always caught a couple games."
Brenly, 25, is in his first big league camp as a player, and has received plenty of attention from the coaches, including early hitting sessions with coach Rudy Jaramillo.
"Sometimes when you come into your first camp, you think maybe you'll be overlooked, but everyone -- Dale [Sveum], Rudy -- everyone has helped me out, and that's stuff I can take through my career," Brenly said. "Hopefully when I come up and help the team, it'll be nice to already have a relationship with them. They don't make any of us feel, 'Oh, you're just the 60th guy.' They make you feel like you're a ballplayer who's going to help us win soon."
The catchers are usually the first ones at the ballpark to get their extra drills done with coach Mike Borzello.
"It gets tough on us as the spring goes on, but when the season comes along and your legs are in shape and you're catching three, four days in a row and you're ready in the ninth inning, it makes you understand why you're working hard now," Brenly said.
He has always been a catcher and has the bruises to show for it.
"It's like being a hockey player with your teeth knocked out -- it just goes with the job," Brenly said.
He'd grab his dad's gear and wear it around the house.
"He wore it, so I wanted to wear it," Brenly said. "It was fun watching a game and I'd be all dressed up like I was playing in it."
When Brenly played with Class A Peoria, he handled a few of the big leaguers in their rehab assignments and has caught Carlos Zambrano and Ted Lilly. He learned from that experience, too, by watching their preparation.
"They were very open with us. We could ask questions and they were very helpful, just like everyone in here," Brenly said. "At some point they were working their way up, too. It's nice they don't forget the process and how to get there. Everyone's been willing to help. It's been great."
Brenly hit .206 at Class A Daytona last season, while Lalli batted .287 at Double-A Tennessee. Right now, they're soaking in as much as they can this spring.
"I think everyone who is here [in big league camp], no matter how you got here, has earned it in some way or another," Lalli said. "You've earned the shot to be given a chance."
Carrie Muskat is a reporter for MLB.com. She writes a blog, Muskat Ramblings, and you can follow her on Twitter@CarrieMuskat This story was not subject to the approval of Major League Baseball or its clubs.