Phillips' absence has only been magnified with the loss of shortstop Zack Cozart for the season, leaving a gap of inexperience in the middle of the infield.
Eugenio Suarez, 23, started at shortstop while two-year veteran Kristopher Negron started at second. Negron hasn't been a regular second baseman for Cincinnati, as Ivan De Jesus has seen more time at that position.
"These opportunities, where we have some injuries and some new guys up there, create opportunities for me to plug guys into different roles and see how they handle it," Reds manager Bryan Price said. "It's one of those unusual times because De Jesus is up here now for his first time and Geno as well. They're just trying to get comfortable being on the team. Even though these guys got to know each other a bit during Spring Training, I'm sure there's still that awkwardness about just feeling like they're a part of the ballclub."
Phillips and Cozart had solidified the defense up the middle, as Phillips' 26 double plays and Cozart's 30 were both good for 10th in the Majors at their respective positions entering Saturday.
Phillips could return Sunday if Price likes what he sees out of pregame workouts. Phillips has been out of the starting lineup with a groin injury since the first inning of Tuesday's game against the Phillies, but he entered as a pinch-hitter on Friday and again Saturday night, driving a sharp flyout to center field while batting for the pitcher in the seventh inning.
"I think the risk/reward is not real good to rush this one," Price said. "Until I see him moving, making more explosive movement, I won't think about starting him."
Phillips' presence likely will be missed Saturday night with pitcher Mike Leake on the mound. Leake "lives on the ground ball," according to Price, and will go the first time without either Cozart or Phillips behind him.
Price and Cincinnati also are waiting to see how quickly Phillips and Suarez can bond on defense.
"I know we'll have Brandon back, but he and Geno are going to have to connect, defensively," Price said. "Geno is a very large part of this ballclub, and in large part, our success will be based on the relationship he's able to build with Brandon up the middle."