CINCINNATI -- It seemed very plausible on Friday night at Great American Ball Park that the next National League Rookie of the Year was on the field.

The leading candidates appear to be Corbin Carroll of the D-backs and, on the Reds’ side, it’s likely Elly De La Cruz. Or is it Matt McLain? How about Spencer Steer?

“We have a lot of really talented rookies on this team," Steer said before the series opener. "Any of them could win it. And obviously Corbin Carroll is an unbelievable player and what he’s doing is pretty special too. I’m excited to share the field with a lot of young talent.”

The Reds’ young talent had its fingerprints all over the 9-6 victory over the D-backs, the club's third win in a row. Steer had two hits and three RBIs, including a two-run double for the go-ahead runs in the fourth inning. But the showcase moment came in the following inning, when McLain slugged his first grand slam as a big leaguer to make it a 9-3 game. McLain was drafted out of high school by the D-backs with the 25th overall pick in the 2018 MLB Draft, but chose to play collegiately at UCLA.

Cincinnati's position players are the fifth-youngest in the Major Leagues  -- including the four rookies in Friday's starting lineup. Arizona, led by Carroll, follows closely with the sixth. Both clubs are surprise contenders for the postseason.

“It makes me wish I was younger but it’s awesome," said Reds starting pitcher Ben Lively, who gave up three earned runs over 4 2/3 innings. "Literally, they’re so energetic and so alive, ready to go every day -- it’s so cool. Watching them get after it, even during their drills and BP and stuff, they’re full-on, going at it. It’s cool to watch, it’s really fun. … I just close my eyes and think, ‘No, I’m not 31. I’m 21.’" 

It was a 2-2 game in the fourth inning when Nick Senzel and McLain worked back-to-back two-out walks against D-backs lefty starter Tommy Henry. Then, on the first pitch, Steer scorched a line drive to the left-field corner to plate both runners.

Steer, who had an RBI groundout in the first inning and a leadoff single in the third, entered the night in a 3-for-35 skid with 13 strikeouts over his previous 10 games. He leads all NL rookies with 95 hits, one more than Carroll.

In the fifth inning, right fielder Will Benson -- a Cincinnati second-year player -- made a nice running catch to rob a hit from Gabriel Moreno. But three batters later, Benson misjudged Ketel Marte's liner and took a step forward before the ball cruised above his head and off his glove for an RBI triple.

Against D-backs rookie reliever Justin Martinez, Benson got the run back in the bottom of the fifth with an RBI ground-rule double to left field that scored rookie Christian Encarnacion-Strand. With two outs and the bases loaded in an 0-2 count, McLain lifted Martinez's 100.9 mph fastball to right field for the grand slam. 

“He blew two past me, the two pitches before. I had to make an adjustment," McLain said. "I made a little adjustment after the first one. It wasn’t enough so I had to start [swinging] earlier. He throws gas.”

In the 57 games since his big league promotion on May 15, McLain is slashing .301/.367/.519 with nine homers and 34 RBIs. He leads NL rookies in batting and on-base percentage.

Following a brief 1-for-11 slump, McLain is hitting .421 (8-for-19) with two homers in his past five games.

McLain is trending back upward, and it's picking up De La Cruz while he's mired in a 3-for-35 (.086) stretch with 16 strikeouts in nine games since the All-Star break. 

“It’s a good feeling to know that there are other guys in the lineup that can do the job," McLain said. "Up and down, one through nine, anyone can beat you. That’s a good feeling to be on this side of it. I’m sure for opposing pitchers and opposing teams, that’s tough. But that’s a good thing for us.”

With a Brewers loss to the Braves on Friday night, the second-place Reds are 1.5  games back in the NL Central race.

The youthful energy of the Reds could be a key factor down the stretch when other clubs might wear down.

“Clearly we’re having a lot of fun doing it," Steer said. "I just think being at the same stage of our careers, all of us being rookies and going through that together, it helps us. We’re doing it together and this is all new territory for us. It’s just a lot of fun doing it with these guys. Watching them have success too is just the cherry on top.”