DETROIT -- The Rays' first wave of September callups were announced prior to the team's Monday afternoon game against the Tigers.

Joining the team Tuesday at Tropicana Field will be right-hander Andy Sonnanstine, who will start against the Red Sox on Tuesday night, catcher Shawn Riggans, right-hander Jeff Bennett and outfielder Fernando Perez.

Maddon called the group "the initial salvo," noting they had ideas about other players who will be called up in September, adding: "But for right now we're doing that."

Maddon explained the moves beginning with Riggans, who got the call over Michel Hernandez.

"The third catcher, especially the way we're working things with [Dioner Navarro] and [Gregg Zaun] really helps a lot having another guy sitting there that can catch," Maddon said. "When you go naked late in the game, when you put them both in, we've done it a couple of times with pinch-hitting situations. It's really an uncomfortable feeling."

Riggans, who started the season on the disabled list, is on the 40-man roster while Hernandez is not, which became an overriding factor on behalf of choosing Riggans.

"We talked a lot about it," Maddon said. "A lot of people here really fought in favor of Michel also, but at the end of the day we decided to go this route. We still love Michel, but under the circumstances and how this all worked out, we had to choose Riggans right now."

Perez will give the team a burst of speed off the bench, which Maddon likes to have as an option as the team goes forward, and Bennett was selected for a specific reason.

"Bennett because he's been pitching as a starter and he's been stretched out now," Maddon said. "We have a doubleheader coming up in a couple of days. And again, we're playing Boston and [Detroit] and then we go to New York. It's a matter of needing more long men rather than just one."

Bennett and Perez will have to wait to travel to St. Petersburg until Tuesday as both will be available for duty with Durham on Monday.