That figures to continue this offseason as well.
Montero made the most of his opportunity to play when Snyder got hurt and grabbed hold of the starting catcher position. Now, unlike the past few seasons, it's Montero who gets the bulk of the playing time, with manager A.J. Hinch getting Snyder in there when he can.
This offseason the pair almost certainly will switch roles again. In the past, it's been Montero's name that has been bandied about in trade talks, but this year it will likely be Snyder's that you hear.
"It's one of those things where I'm past it," Snyder said of the changing roles. "It's pretty clear what route they are going. I've already set myself up to where I'm not going to be surprised by anything. I'll see what happens."
It would have been hard to predict this scenario last December, when Snyder inked a three-year, $14.25 million contract extension that included a team option for 2012. The team seemed committed to him and even had a pair of ballpark giveaways featuring him this year, including a bobblehead night.
"Last December, I signed that deal for financial security, security for my family," Snyder said. "There was no guarantee that it was going to be this team that was going to be cutting me my paycheck for the next few years, so I knew that going in. Looking back at the way things have turned out, I'm really fortunate that I signed it."
A back injury put him on the disabled list in June, though he said it had bothered him throughout May as well. While he was out, Montero started hitting and has not stopped.
Heading into Tuesday's series with the Giants, Montero is hitting .292 with 12 homers and 44 RBIs in 308 at-bats. Snyder, meanwhile, is hitting .200 with six homers and 22 RBIs in 165 at-bats.
In addition, Montero's defense and his ability to handle pitchers has improved, which has long been Snyder's strength.
"Things change quickly, very quickly," Snyder said. "You have to accept things that are out of your control. I've played about one month of the season when I've been healthy. If I'm healthy all season, is it a different story? I don't know. I'm not going to use it as an excuse. You can't argue with what Miggy has done. He's grabbed the opportunity. It's not a surprise. He's a good player."
The Snyder-Montero combination has worked well for the D-backs the past few seasons, and they could go with it next year as well.
But with holes to fill and not a lot of trading chips to use, hanging on to Snyder as a backup might not prove to be the best use of their resources.
"Forever it was Montero was the protection against an injury to Snyder," Hinch said. "Snyder would get hurt and Montero would step in. It's hard to argue the combination of both of them worked. As an organization we were in a perfect spot. It's tough on their careers, it's tough on them and their preparation, but I feel like each of them has maintained the right mentality even though it's been difficult because they both want to play."
Steve Gilbert is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.