A return to the mound in 2020 is starting to look a lot more realistic for A.J. Puk after reaching a milestone in his rehab process on Friday.

After a three-week period of throwing strictly off flat ground, Puk, Oakland’s No. 3 prospect per MLB Pipeline, threw his first bullpen session since landing on the injured list with a shoulder strain just before the start of the regular season.

Puk threw 20 pitches in Friday’s session at the club’s alternate training site in San Jose. The left-hander is scheduled to throw again on Monday, increasing his workload to 30 pitches.

When asked before Saturday’s game against the Giants if he expects Puk to pitch in the big leagues this season, manager Bob Melvin said, “I do. We’re not even at the halfway point. Hopefully, we get him back this year.”

Puk was set to move into the rotation this season after impressing in his short time with the A’s last year out of the bullpen. However, Melvin recently mentioned that Puk would likely pitch out of the bullpen upon returning to Oakland and there might not be enough time to build his arm up into a starting role given the shortened 60-game regular season.

Puk proved to be a valuable asset in relief for the A’s in 2019. Showing off a fastball that touched triple digits, the lefty posted a 3.18 ERA in 10 relief appearances for the A’s last season, striking out 13 batters over 11 1/3 innings.

Montas hopeful for return in Arizona

After Frankie Montas was scratched from Friday night’s start against the Giants with upper back tightness, Melvin was hopeful that the right-hander would be able to pitch at some point in the three-game series against San Francisco. While Montas felt better on Saturday, Melvin revealed that Mike Fiers would start Sunday’s series finale in San Francisco.

The A’s are taking a cautious approach with Montas, who is off to a strong start this season at 2-1 with a 1.57 ERA over four starts, while striking out 22 batters and walking just nine in 23 innings. Expected to throw a bullpen session over the weekend, the earliest Montas will be available to start a game is Tuesday, when the A’s play the second game of a two-game road series against the D-backs.

“I don’t know that tomorrow is a good idea. We’re probably looking more like the Arizona series,” Melvin said Saturday. “ The fact we had an off-day [on Thursday] and everyone pitches on a normal turn, it wouldn’t be the right thing to push him tomorrow.”

Hendriks brings the heat

The slightly decreased velocity on A’s closer Liam Hendriks’ fastball to begin the season went mostly unnoticed after converting five of his first six save opportunities. But in Friday night’s 8-7 win over the Giants, that overpowering heater made its return.

Hendriks closed out his sixth save of the year on Friday by striking out all three batters he faced in the 10th inning. He did it on 13 pitches, all of which were fastballs of at least 97 mph or above.

“You’ll see certain pitchers start out slower than others after an abbreviated camp. We were seeing 94-95 mph first time out. Saw some 98s last night,” Melvin said Saturday. “In that situation, there’s certainly some adrenaline going when you come in with a man on second base and a one-run lead. It’s not your normal save. The intensity is there right away, and it certainly looked like it for him. To strike out three guys in the fashion that he did was impressive.”

Over his last nine outings, Hendriks has allowed just one run on five hits in 9 1/3 innings. Coming off the first All-Star campaign of his career, Hendriks has carried over the success to 2020, entering Saturday night with the second-most saves in the Majors. Since the start of the 2019 season, Hendriks leads all American League relievers with 139 strikeouts.

Having faced Hendriks during simulated games in Summer Camp, A’s first baseman Matt Olson is glad to be playing behind him on defense rather than having to step into the box against him.

“You know he’s going to be aggressive with the heater, but somehow you still can’t catch up to it,” Olson said. “He’s got good life on it, on top of it being upper 90s. He’s coming at you with the fastball and locates it well. That’s why he can do what he does by just throwing mostly heaters.”