It is widely assumed that Iwamura is appealing his three-game suspension (which was set to start Wednesday) at least in part to help avoid a scenario where both Bartlett and Iwamura are unavailable.
"At this point, all I can tell you all is we are appealing," Iwamura said, of the punishment doled out for the June 5 fracas with the Red Sox. "Personally I wanted to appeal, and the team wanted to appeal."
The appeal also keeps Iwamura in the lineup for the remaining two series of the homestand, as the club is expecting to get a hearing date from Major League Baseball early next week.
The Rays are hoping Iwamura will help anchor the infield, as they prepare for the likelihood of missing Bartlett at shortstop. His wife, Kelly, is approaching her due date, and the couple plans to induce labor next Wednesday if the child hasn't already arrived.
Manager Joe Maddon said the Rays are anticipating two days off for Bartlett for the family matter, but did not foresee giving the shortstop an additional scheduled day off anytime soon, as the Rays have four off-days already in June.
While Iwamura could wait and have his appeal heard, the club could also opt to drop the request depending on Bartlett's situation.
Although it is impossible to guess a timetable for the scenario, what Bartlett and Iwamura have done for the Rays' defense is much more conclusive.
"Just totally different," B.J. Upton said of the revamped middle infield. The Rays center fielder noted that Bartlett gets to a number of balls that Upton would have had to field in years past.
"Most definitely, [Bartlett's] been an improvement from what we've had," Carl Crawford said. "Not to say [anything] bad about the guys that we had. But he's been catching a lot of balls up the middle, making a lot of plays, so he's been helpful for us, definitely an upgrade."
"[Bartlett] and Aki, they've been working good together," he added.
In their first year working together, both infielders have made seamless adjustments for the Rays.
Bartlett came to Tampa Bay in an offseason trade with Minnesota, while Iwamura made the switch from third base to second base this spring, in anticipation of rookie Evan Longoria's arrival.
Their chemistry was apparent immediately in Spring Training, and the results are a large part of the Rays' success so far this season.
Entering Wednesday night's contest, Bartlett has committed just four errors in his last 49 games, while Iwamura is one of only two Major league second basemen who are errorless on the season.
Iwamura's 50 double plays ties him for second in the Major Leagues at his position, and a big part of that success has been Bartlett's swift glove.
"They turn double plays that probably shouldn't be double plays," Upton said.
Brittany Ghiroli is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.