TORONTO -- Though the latter part of Saturday’s 10-8 loss to the Blue Jays saw a continuation of the A’s bullpen struggles, with multiple relievers struggling to hold down Toronto’s offense, the early portion saw the bullpen’s most inexperienced arm provide a major contribution.

Daulton Jefferies drew a tough assignment in what was only the second relief outing of his Major League career. With starter Paul Blackburn departing in the fourth with two outs, Jefferies was summoned with runners at the corners and Blue Jays slugger Vladimir Guerrero Jr. coming to the plate. Retiring Guerrero with a flyout to keep Oakland’s deficit at 4-0, Jefferies began an impressive outing that saw him toss 2 1/3 scoreless innings while allowing only one hit.

“Daulton came in and did a nice job,” A’s manager Bob Melvin said. “He kept us right there at the time, and then we gave up the runs later.”

Jefferies, Oakland’s No. 5 prospect per MLB Pipeline, was called back up to the big leagues from Triple-A Las Vegas on Aug. 27 with the expectation of providing long relief in the event a starter is unable to go deep, as was the case on Saturday afternoon.

Given the recent struggles from several members of the A’s bullpen, which entered Sunday with seven blown saves and a 7.85 ERA over their last 13 games, could Jefferies elevate his role to higher-leverage situations? Melvin hinted at a possible shakeup of bullpen roles, especially with former closer Lou Trivino struggling to regain his early-season form with 13 runs allowed on eight hits and five walks over his last five appearances.

“We’ll see going forward,” Melvin said. “We’ll figure out where everybody plays out right now. Things could change a little bit, certainly with Lou not getting back to the form where we’ve seen him.

“More than anything, for a guy who hasn’t pitched a ton at the big league level to come in with runners on base and go through that lineup for a couple of innings with success, I think that does wonders for him.”

Jefferies quickly noticed the change of pace that comes with pitching in relief. For one thing, there’s an adrenaline rush that far surpasses the feeling that comes when starting. But it’s not a completely foreign concept for the right-hander, who made 12 relief appearances in the Minors.

“I definitely had some adrenaline getting hot in the bullpen,” Jefferies said. “I felt good. I’ve gotten a lot more comfortable on the mound at the big league level.”

Confidence is often a key ingredient to a young pitcher’s success, and Jefferies is no different. After a Major League debut that did not go so well in 2020, Jefferies returned for his first 2021 stint with the A’s on Aug. 1 for a spot start against the Angels. He picked up his first Major League win after a solid outing of three runs allowed over five innings.

Though he was sent back down shortly after that August outing, Jefferies carried the confidence he gained with him and brought it back in this most recent callup.

“I think the biggest thing was getting my confidence up and knowing I can pitch at the big league level,” said Jefferies. “I know I can get guys out. My job out of the bullpen this year is get outs and hand it off. It’s been a learning curve of getting my feet wet and getting comfortable.”

Jefferies still projects as a starter for the long term at this point. That opportunity to join the rotation could come as early as next season. As for a promotion to a later-inning role out of the bullpen this year for a club in the middle of a playoff race, Jefferies said he’s up for anything.

“I understand my role,” Jefferies said. “Come in and get as many outs as I can. If they want to have me go long, great. If they want me to face a couple of guys, that’s great, too. My job is pretty simple. Just come in and get outs. I’m just happy to be here and happy to help.”