NEW YORK -- MLB commissioner Rob Manfred defended the end-of-game replay rules that might have cost the Cincinnati Reds a game and boosted the St. Louis Cardinals' playoff chances in the final week of the season.

The Cardinals won their Sept. 29 game against the Reds when Matt Carpenter scored on what replays showed should have been a ground-rule double, which would have sent Carpenter back to third.

No replay was initiated because Reds manager Bryan Price didn't ask for it immediately after the game ended. Manfred said he doesn't think the incident indicates there is a problem with replay.

"There was a call. It was missed," Manfred said. "Replay was available via manager challenge, and the manager, if you think about it, the manager elected or did not opt to challenge within the confines of a clearly defined rule. I mean, it says 'immediate' in the rules."

Manfred said the immediacy rule is necessary for two reasons. Managers have no reason to retain a replay challenge if there is a game-ending play. And players often douse one another with a beverage or retreat to the clubhouse, causing a disruption in the competitiveness of the game after walk-off plays.

"People throw Gatorade on people and players get off the field," Manfred said. "And bringing folks back out on the field after some of those things have happened in order to continue a game because of a replay call is not appealing."

One notion that has been brought up in the wake of the missed call is having replay officials in New York immediately review game-ending plays after they happen, much as they do in the NFL.

Manfred said he's also not a fan of that idea.

"We opted for the challenge rule and have tried to stay pure on the challenge rule given the number of calls in a game," commissioner Rob Manfred said. Nick Turchiaro-USA TODAY Sports

"We opted for the challenge rule and have tried to stay pure on the challenge rule, given the number of calls in a game, figuring the best way to decide which ones really mattered is to let the people playing the games decide," Manfred said. "Whoever's involved in bedlam after one of those games, there should be one guy who has his wits about him. That's why they call him the manager."

In addition to sharing his thoughts on replay, Manfred said an MLB investigation into hacking by one of the Cardinals' former employees into the Houston Astros' data bases could be forthcoming. The Cardinals could be hit with penalties, such as losing a draft pick or having limits placed on their international signings.

"It will not be a next-year resolution. We are in the process of finishing up our investigation. Candidly, I wish it had gone a little faster. I wish it had gotten a little more help a little sooner from the U.S. attorney's office," Manfred said. "But the cards come up how they come up, and we're going to finish our investigation, and there will be a resolution of that during this offseason."