They believe that Walker Buehler will once again be the pitcher he used to be, that he can once again be the man unafraid to scale the mound when the games count the most.

But how much will they stake on that belief?

Buehler’s second start wasn’t any better than his first, the former All-Star removed from a 4-0 defeat to the San Diego Padres with just one out in the fourth inning.

His final line on Sunday at Petco Park: Three runs, five hits, two walks, two strikeouts.

“I think that we just can’t lose sight of the fact he hasn’t pitched in two years,” manager Dave Roberts said.

Roberts was right, of course.

Buehler had pitched only once in the last 23 months after undergoing Tommy John surgery for the second time. But the challenging circumstances don’t change the situation. As much as the Dodgers are viewed as automatic postseason entrants, they still have to win enough games to qualify to play in October. They can’t count on the second-place Padres to be a .500 team forever, not after the Padres won two of three games against them during the weekend.

In which case, how much longer can the Dodgers send Buehler to the mound every six or seven days if he continues to pitch like this?

“I think given what he’s gone through, what we’re hoping he can be, expecting him to be, he’s going to get as much as he needs,” Roberts said.

Once again, Roberts was right. The Dodgers have to give Buehler as long a leash as he needs.

It’s an organization that measures success in championships, not regular-season wins. Does it really matter if the Dodgers win 110 games instead of 100 if they choke again in the playoffs?

Buehler is a potential game changer.

Imagine if Tyler Glasnow remains healthy, if Yoshinobu Yamamoto continues to build on his recent success and Buehler starts resembling the pitcher who used to be the Dodgers’ Game 1 starter.

The Dodgers would have three front-line pitchers, something they’ve never had under the management of Andrew Friedman.

Buehler’s arm could redefine their rotation.

Buehler’s attitude could recharge the clubhouse.

Something else: Buehler pitching well would lessen the urgency for the Dodgers to acquire another starter at the trade deadline, allowing them to turn their attention to other areas of concern, such as their bullpen and infield defense.

There’s no reason for them to not to be exceedingly patient with Buehler, especially with a 5 ½-game lead in the National League West.

“Anyone is going to deserve — certainly with his track record — a handful, five, six starts,” Roberts said.

Buehler prepared for his comeback by pitching in six minor league games, but questioned their efficacy.

“Listen, man, like throwing games in the minor leagues, you’re never gonna learn how to get big leaguers out,” Buehler said. “I think that’s kind of where we’re at.”

And that’s what Buehler looked like against the Padres, a pitcher making only his second start in two years.

Especially problematic was how he couldn’t miss any bats with his trademark fastball, which averaged close to 96 mph. Of the 77 pitches he delivered, 27 were four-seam fastballs. He generated a swing-and-miss with only one of them.

Eight of the first 10 pitches Buehler threw were fastballs, two of which were hit for first-inning home runs by Fernando Tatis Jr. and Jake Cronenworth.

But this is part of the process, Buehler learning whether he can still bully hitters with heaters or has to figure out new methods to get them out.

“I’ve got to get reacclimated to being here,” Buehler said. “I was probably 94-95 [mph] with my best throws in triple A. Now, it’s a little above that. There’s times and deliveries and at-bats that I feel like, ‘Oh, I can still run through people if I want.’ And then people show me that’s not the case.”

Buehler knows what he’s up against. Only a handful of pitchers have thrived after a second elbow reconstruction. He said he was trying to be patient.

The Padres’ Fernando Tatis Jr. celebrates after hitting a home run during the first inning against the Dodgers on Sunday.

(Gregory Bull / Associated Press)

But …

“I think it’ll be before 10 starts that I’ll start getting really angry at myself if it keeps going like this,” Buehler said. “But I think the next three or four starts, still trying to figure it out and put some things in the rotation.”

He knows he’ll continue to receive opportunities, but that he won’t receive them forever unless his performance improves.

“You know, I want to stay in the rotation,” Buehler said. “We have a lot of talented people here. Most people believe that if you’re not putting the team in a really good position to win, you shouldn’t be starting games. So I’m trying to give myself a little grace period to not freak out. In saying that, I’m not freaked out. I’m actually pretty encouraged by a lot of things I’ve done.”

He said he was encouraged by how he warmed up better than in his first start and how he was less fatigued after the first inning.

That was enough for Roberts. The 162 games in the regular season aren’t the Dodgers’ primary objective. The 11 games they have to win in the postseason are. For now, their most likeliest path to those 11 victories include Buehler.