Sean Manaea’s evolution as a pitcher this spring has been well-documented, but in his final spring outing, he offered a glimpse into his emotional growth.

Manaea’s afternoon was headlined by his exhibition of tranquility, bouncing back from a frustrating third inning to retire the side in the fourth and finish his afternoon, as well as his spring, on a high note in the A's 7-2 loss to the Giants.

“When I was younger, I definitely would’ve let that stuff affect me,” Manaea said. “It definitely did affect me in a certain way, but I feel like the way I carried myself was OK. I definitely work on controlling it better, washing things away, just living in that moment.”

The third inning was a rough endeavor for Manaea. After striking out the leadoff batter, Manaea allowed five straight batters to reach base before temporarily exiting. Manaea didn't get close calls around the zone and expressed visible frustration toward home-plate umpire Alex Tosi as he walked off the field, according to the radio broadcast.

When Manaea reentered in the fourth, he didn’t allow any negative carryover. The turbulent frame was quickly forgotten, and Manaea responded by briskly retiring the side in order. If the third inning was mired by frustration, the fourth was defined by a display of equanimity.

The numbers from Manaea’s outing weren’t great -- the southpaw allowed five runs and four walks while striking out five in 3 1/3 innings -- but his ability to exercise a short memory mattered more than the results themselves.

“That’s not going to be the last time stuff doesn’t go my way,” Manaea said. "It’s just part of the game. Being able to move on and get outs, that’s the ultimate point.”

It was an impressive end to an important spring for Manaea, who dedicated the preseason to familiarizing himself with an old tool.

Manaea’s velocity has gradually dipped since debuting in 2016, dropping from 93 mph as a rookie to 90.4 mph last season. The decrease in velocity was not due to any physical ailments, but rather Manaea’s emphasis on precision.

With Manaea having established his command -- he ranked in the 97th percentile in walk rate last season -- he brought heat back into the fold. While Manaea’s average fastball velocity from this spring is unknown, he regularly sat in the 93-94 mph range, the hardest he’s thrown since his first several years.

Interestingly enough, Manaea has had an uncharacteristically erratic spring, walking nine batters and plunking three in 15 1/3 innings.

“I did well without throwing hard for a couple of years and that really made me learn how to pitch,” Manaea said earlier this spring. “Having some more velo now and having learned how to pitch I think will take me a long way. I think it’s just going to keep increasing.”

Roster moves

Outfielder Ka'ai Tom has made the Opening Day roster and reliever Burch Smith will take up the final bullpen spot, manager Bob Melvin announced Monday morning.

For Tom, who slots in as Oakland’s fourth outfielder, this marks the first time that he will crack a Major League roster.

"I told him yesterday. He was pretty excited, obviously,” Melvin said Monday.

Tom earned the spot not just with his bat, but his defensive versatility. In 11 Cactus League games, Tom slashed .310/.412/.552 while roaming all three outfield positions.

Tom’s promotion to the big league club comes following the news that infielder Vimael Machín and outfielder Seth Brown were optioned to Triple-A. Brown, who hit .226 with three home runs this spring, was in competition with Tom for the fourth outfield spot.

While Brown and Machín will begin the season in Las Vegas, Melvin expects both to make appearances for the A’s in due time.

"We start with 26, but we always feel like we have a group of 32 guys that are really a part of this team,” Melvin said. “I believe all of them are going to contribute.”

On the reliever front, Oakland’s eight-man bullpen is now finalized. The relief corps will feature Smith, Trevor Rosenthal, Jake Diekman, Yusmeiro Petit, Sergio Romo, Adam Kolarek, Lou Trivino and J.B. Wendelken.

Smith was limited to just six appearances last season due to a forearm injury, but appeared to finally put the pieces together. In 12 innings, Smith allowed only three runs -- all of which came in his final outing -- while striking out 13 batters. 

Worth noting

• Melvin said Oakland’s rotation for the first five games of the season will depend on how Frankie Montas feels after pitching in an upcoming simulated game that’s scheduled on an off-day.

Chris Bassitt and Jesús Luzardo will start Oakland’s first and second games of the season, respectively, but those are the only two rotation spots currently set. The order of the other three spots -- Manaea, Montas and the undetermined fifth starter -- are still up in the air.

• The A’s lineup in their final spring game looked very similar to a configuration they could employ on Opening Day. Melvin said there might be some adjustments to the lineup, not willing to completely tip his hand, but confirmed that it was similar to what the team might roll out.

• Mike Fiers is “doing well,” per Melvin, and is scheduled to pitch two innings along with Montas in the aforementioned simulated game. Melvin said Fiers will likely spend some time at the alternate training site and continue pitching to hitters. The goal is for Fiers to rejoin the team in mid-to-late April, although Melvin did not specify a timeline.