CINCINNATI -- Nothing is guaranteed.

It is true, even for Spencer Turnbull, who has a 1.33 ERA in five starts with the Phillies. Turnbull’s ERA is tied for the fourth-lowest in baseball, which is something considering he signed a one-year, $2 million contract in February to be starting pitching depth. But on Wednesday, Turnbull was asked about possibly moving to the bullpen in the next few days, despite pitching so well, because Taijuan Walker is scheduled to make his 2024 debut on Sunday in San Diego.

“All of that stuff is out of my control,” he said following Wednesday night’s 7-4 loss to the Reds at Great American Ball Park. “Obviously, I’m aware of things. … If they want me to start, I’m going to start and give my team the best chance to win. If things change, things change. But hopefully I pitched well enough to give myself a chance to stay in that conversation. I know there’s other factors involved and stuff like that, but they haven’t said anything to me yet, so I’ll just get ready to prepare for my next start and see how it goes.”

Turnbull allowed three hits, one run, three walks and struck out eight in five innings against the Reds. He threw 89 pitches. He would have started the sixth, but the Phillies had a long top of the sixth. The Phillies chose to protect Turnbull’s arm and hand a 3-1 lead to the bullpen.

Seranthony Domínguez allowed four runs in the sixth to give the Reds a 5-3 lead.

If the bullpen had done its job, the Phillies would have been 5-0 in Turnbull’s starts. But even that probably would not be enough to keep Turnbull in the rotation. Walker is in the second year of a four-year, $72 million contract. He went 15-6 with a 4.38 ERA in 31 starts last season. He threw 172 2/3 innings.

For those reasons, Walker earned the opportunity to start again.

“He’s throwing the ball well. He has,” Phillies manager Rob Thomson said about Turnbull. “But we’ve got a 15-game winner coming. He threw the ball pretty well for us last year. In the middle of the summer, he was as good as anybody in baseball or in the National League, anyway. So, we’re hoping to get that guy back.”

The Phillies have said they also need to monitor Turnbull’s workload. He has not pitched more than 56 2/3 innings since 2019. Moving him into the bullpen will allow them an opportunity to better manage that.

A six-man rotation is not in play, at least not now. The Phillies used one last season, but they said it doesn’t make sense this early, especially with two off-days coming in the first nine days of May.

For all those reasons, signs point to Turnbull in the ‘pen, although the Phillies have said repeatedly no decision has been made because they are considering different options.

Asked how he would take a move to the bullpen, Turnbull said, “I’m not sure. I’ll cross that bridge when I get to it. I’ll do whatever they tell me. Like I said, it’s not my decision. Whatever is going to give the team the best chance to win, is what I want to do. If they see that going in a different direction, that’s fine. I’ve enjoyed my five starts so far. I feel great. I feel strong. I feel healthy.”

Nothing is guaranteed.

But if it holds true for Turnbull, it also holds true for Walker.

“Now it’s up to him to go out and pitch well,” Phillies president of baseball operations Dave Dombrowski said. “Nothing comes in perpetuity, right? He’s earned the ability to do that. But now he has to go out and perform. We think he will. If he doesn’t, then we’ll tackle it at that time.”

The Phillies have not used fewer than nine starters in a season since 2011. So bet on Turnbull to be back at some point.

“It’s only five starts so I don’t want to get too ahead of myself, but I’m very happy with how I’ve pitched,” he said. “My teammates are happy with it. Hopefully I can keep that rolling. I don’t know if ‘expecting’ is the right word, but just looking for a good situation to sign with the right team and put myself in a good position to make a starting rotation. If not, make a team somewhere. Be in the big leagues. Obviously I didn’t want to go to Triple-A. I feel like I’ve at least proven I belong in the big leagues.”