SURPRISE, Ariz. >> The Giants will roll into Cincinnati in roughly a week for Opening Day at Great American Ballpark, and a good chunk of the players remaining in major league camp have an idea where they’ll start their season.

For a select few, their futures remain uncertain.

Will the Giants select Hayden Birdsong, Landen Roupp or Kyle Harrison to be their fifth starter? And what happens to the two starters who don’t make the cut? What about the final spots in San Francisco’s bullpen? Does the bench look any different now compared to the beginning of camp?

With Cactus League play coming to a close, here’s how San Francisco’s key positional battles are shaping up:

Fifth starter

Harrison has been playing catch-up for the entirety of camp after losing 10-15 pounds right before spring training. Birdsong and Roupp have both thrown 12 innings this spring and have been stretched out to throw at least five innings. Harrison, by contrast, has only thrown 6 2/3 innings, his longest outing this spring being three innings. Following Harrison’s outing against the A’s on Sunday, manager Bob Melvin said it “might be hard” for Harrison to get fully stretched out in time for the season.

“We’ll see where we are with him,” Melvin said on Sunday. “He’s a little bit behind everybody. Today, getting him three innings and it seemed like there was a little bit more life in his arm. Like I said, it was a step in the right direction.”

If Harrison is out of the running, that leaves Birdsong and Roupp as the final two candidates. And of those two, Birdsong likely has the edge. Not only does Birdsong have a 0.75 ERA with 18 strikeouts, but the 23-year-old hasn’t walked a single batter during Cactus League play, no small feat for someone who walked 13.7% of the batters he faced last season.

Roupp has had a fine spring in his own right. Along with a 3.75 ERA and 14 strikeouts to one walk during Cactus League play, Roupp threw five scoreless innings with 13 strikeouts against Colorado Rockies minor leaguers last week. That said, it’s hard to overlook the combination of Birdsong’s spring performance and last year’s tantalizing strikeout numbers (72 innings, 88 strikeouts).

“It’s been kind of cool to follow,” Melvin said. “Like I said, (Harrison) is probably a little bit farther behind as far as his progression, but Roupp and Birdsong have really been fantastic.”

So, does that leave Roupp destined for Sacramento? Not quite. There’s also the matter of the …

Bullpen

Should Roupp land in the bullpen, the Giants would have to sacrifice — at least in the short term — keeping him stretched out as a starter. That, in turn, would leave Harrison as the next starter in line should anything happen to the quintet of Brandon Webb, Justin Verlander, Robbie Ray, Jordan Hicks or Birdsong.

Roupp would join a bullpen that will feature closer Ryan Walker, Tyler Rogers, Camilo Doval, Erik Miller, Sean Hjelle and Randy Rodríguez. As for the eighth and final spot? There are several compelling candidates.

Joey Lucchesi, a Newark native, hasn’t allowed a run this spring, can throw multiple innings and would give the Giants a second left-hander. Joel Peguero, a non-roster invitee capable of hitting 101 mph, also hasn’t allowed a run this spring. Tristan Beck and Spencer Bivens are both right-handers with major league relief experience. But the true favorite to round out the bullpen is Lou Trivino.

Trivino, a non roster invitee, hasn’t pitched in the majors since ’22 after undergoing Tommy John surgery in ’23, but has pitched 7 1/3 scoreless innings this spring. It’s also hard to ignore that Trivino has a relationship with Melvin from when they were both with the A’s. Selecting Trivino over Lucchesi would leave the Giants with one lefty (Miller) in their bullpen to start the season, but San Francisco has not been intent on having two left-handers in its bullpen.

Bench

Tom Murphy will likely start the season on the injured list, leaving the Giants two main choices for backup catcher: Sam Huff and Max Stassi. Huff, who was claimed off waivers, is already on the 40-man roster; Stassi is a non-roster invitee. Huff has flashed impressive power this spring and has often started on days when Patrick Bailey is off.

Luis Matos, a right-handed hitter, gets the edge over Grant McCray, a left-handed hitter, because Matos can platoon with right fielder Mike Yastrzemski. McCray is also in need of more seasoning with Triple-A Sacramento after striking out in 43.1% of his plate appearances with the Giants last season.

With Huff, Matos and Jerar Encarnacion occupying three of the four bench spots, San Francisco will likely roll with Brett Wisely over Casey Schmitt because Wisely provides the Giants with a left-handed bat off the bench.