DENVER -- The Giants traded from an area that was regarded as having surplus when they dealt relievers Mark Melancon, Sam Dyson, Drew Pomeranz and Ray Black prior to Wednesday’s Trade Deadline. After all, they still have All-Star Will Smith at the back end of what has been a strong bullpen in 2019, not to mention the likes of Tony Watson and Reyes Moronta, who have been very reliable.

But in Friday’s 5-4 loss to the Rockies at Coors Field, it was that post-Deadline bullpen that couldn’t hold a 4-2 lead in the sixth inning after Mike Yastrzemski obliterated a 472-foot shot off the facing of the third deck in right field to break a 2-2 tie in the fifth.

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There are new faces in the bullpen following the Trade Deadline, symbols of the confidence Giants president of baseball operations Farhan Zaidi and the rest of the front office have in San Francisco’s depth there.

Sam Selman, Jandel Gustave and Andrew Suárez were sitting beyond the right-center-field wall Friday night after being called up from Triple-A Sacramento on Thursday, and two of them -- Selman and Suarez -- were called upon to contain a Rockies offense that has been very good at home despite Colorado’s recent slide from contention.

Selman gave up the biggest hit of the night, a game-tying, two-run homer over the center-field fence by Ryan McMahon in the sixth. McMahon was the first batter Selman faced in his second career appearance after making his Major League debut the day before in Philadelphia, and he left a fastball that was meant for the outside corner right over the heart of the plate.

“You don’t know. You just don’t,” manager Bruce Bochy said of how a transition with fresh relief arms might go, particularly when they have little Major League experience. “You look how they’ve been throwing the ball [Selman had a 1.35 ERA and 43 percent strikeout rate in 30 Triple-A appearances], and you have confidence in the kid. I’m sure he’d like to have that pitch back. But I’m sure he’ll get settled in here.”

How the transition goes after the departure of Melancon, a former lights-out closer who has had injury troubles but has gotten back on track the past couple of seasons, as well as Dyson, who gave San Francisco a 2.47 ERA in 49 appearances, could very well determine whether the Giants have a real shot at playing a National League Wild Card Game in early October.

As for Moronta, who yielded a go-ahead RBI double to pinch-hitter Ian Desmond in the seventh, this is, indeed, what Bochy called “a hiccup” for the relief corps.

“I’m not going to say every day is going to be perfect in baseball,” Moronta said through an interpreter. “Everything is good with me. Today, my slider was just going too far out.”

Moronta went to three-ball counts to each of the first three batters he faced in the seventh. With his inability to locate his slider and changeup, he was forced to come in with the fastball, resulting in a Charlie Blackmon single, a Trevor Story walk and Desmond’s double off the wall in right.

A bright spot in the midst of all this was Suarez’s outing. He relieved Moronta with one out in the seventh and runners at second and third. He got Daniel Murphy to hit a weak ground ball to Scooter Gennett at second, and Gennett threw out Story at the plate on a safe call that was overturned on replay.

Suarez then struck out McMahon looking on a 94.7 mph fastball to escape the jam

“What a great job he did,” Bochy said. “He gave us a chance to win, and we just came up a little bit short. In the eighth inning, we had [Gennett] on second and [Steven] Duggar just missed that ball [on a flyout to right].”

Bochy said he can see Suarez as a potential “Swiss Army knife” type of reliever going forward.

“Especially after yesterday, putting him in on back-to-back days, and I put him in a tough situation,” Bochy said. “I wanted to save Moronta, with him getting up there a little bit in pitch count.”

In the end, the Giants hope to look back at this period in the season, in the immediate wake of a bullpen reshuffling out of the Trade Deadline, the way Selman described his hope for the next two months and, hopefully, beyond.

“You hope [the transition] will be quicker than you possibly can,” Selman said. “You’re just trying to eliminate mistakes and learn from what you did. You get back in there soon.

“So you just get back in the saddle and do it again tomorrow.”