CINCINNATI -- One of the decisions a manager wrestles with almost daily is when to give one of his regulars a game off. 

When one of those regulars is struggling, the decision becomes a bit clearer, if not easier. 

Such was the case with the Cardinals' Tyler O'Neill on Saturday. The outfielder came into the game mired in an 0-for-13 slump and was hitting just .194 (6-for-31) in the first eight games of St. Louis' 10-game road trip through Milwaukee, Miami and Cincinnati. 

“Even going into the day [Friday], I had figured [Saturday] would be a good day to give him,” Cardinals manager Oliver Marmol said. “[I] had a good conversation with him, and he felt like he agreed, having a little mental break [Saturday] and going back at it [Sunday] probably makes sense. He feels like he's close, and I agree with him. It's just a matter of sometimes, you just need a day not to think."

The road trip is tough enough. Add to that the arms the Cardinals are facing, and slumps are easily understood. 

"When you really think about our stretch this road trip we've been on, you've got Milwaukee, and they still got [Brandon] Woodruff, [Wily] Peralta and [Adrian] Houser," Marmol said. "And then you go to Miami and you've got [Sandy] Alcantara ... and [Pablo] López and the [Jesús] Luzardo guy, and you come here and face [Hunter] Greene day one, that's a lot of good arms in a row."

Then the Cardinals are in line to face the Mets' Max Scherzer to open a homestand Monday at Busch Stadium. 

"Keep 'em coming,” Marmol quipped. 

The Cardinals' top two sluggers -- Nolan Arenado and Paul Goldschmidt -- have played in the first 13 games, with no set time for a day off. 

"Potentially not," Marmol said. "I'll sit with both of them [Saturday] and kind of go through that with them as far as scheduling it, but no, we trust our other guys. Obviously, we want those guys in our lineup every day, but you try to find that day before they need that day."

There are days when players don’t start, and others when the player is not available unless there’s an emergency, such as an injury. So what’s the difference?

"That's a great question and one I'll never answer. Our guys are always available,” Marmol answered initially, before adding, "There are days where guys need a full day of not even thinking about grabbing a bat. We pick those days and let the player know that day."

Resting a player is usually more about giving him the day off from even thinking about the game. But there’s always the chance the player approaches Marmol and tries to talk himself into action. 

"That's usually what happens,” Marmol explained. “There are times where you say, 'I appreciate it, but don't put your cleats on today unless there are crazy injuries and I need you. I feel like even if a big situation comes up, I [still] need you to take a full day and just rest. There are days where you tell a player that. 

“Then there are days where they have a day off, be ready late in case a big situation comes up. It just depends on our read of what that player really needs at that moment. If they really need a full mental day of nothing, then that's appropriate."