SCOTTSDALE, Ariz. -- Matt Cain's race against time to join the season-opening starting rotation will accelerate Friday when the Giants right-hander faces the San Diego Padres in his first Cactus League appearance of the spring.
Cain and the Giants were encouraged by the simulated game he pitched Monday. He worked the equivalent of two innings, throwing 30 pitches to Grant Green, Ryan Lollis and Mac Williamson. Assuming Cain feels nothing other than typical post-pitching soreness, he'll keep Friday's starting assignment.
"It was a good session for him. It went very well," Giants manager Bruce Bochy said, noting the veteran threw an assortment of pitches, including breaking balls and changeups. "I know he feels good about how it went."
• Spring Training:Schedule | Tickets | Information
Cain, whose progress this spring was delayed by removal of a cyst on his throwing arm, sounded upbeat about more than just Monday's exercise.
"I feel confident, the way things have gone the past week, with the throwing, after the bullpens [and trying] to increase the intensity today," Cain said Monday. "I might be a little more sore tomorrow, but it'll be like a normal soreness [from] facing guys, which will be good."
Should Cain avoid further physical setbacks, he should be able to start four exhibition games. That could be enough to give him the stamina to handle a six-inning workload, which probably will be the basis for determining whether he's fit to start.
But while Cain's ideal pitching schedule can be scripted, his physical reaction to steadily increasing his workload cannot. At this juncture, it's impossible to predict whether the 31-year-old will build the endurance he needs by the first week of April.
Cain acknowledged that he and the Giants' decision-makers will have to evaluate day by day whether he's progressing sufficiently. If he isn't, Chris Heston likely will replace Cain in the rotation to begin the season. Heston looked ready for the regular season Sunday while surrendering one hit in four shutout innings against San Diego.
"I think we'll try to get the pitch count as high as we can, if everything keeps going like it has been, and then figure out what we'll do toward the end if I feel fine," Cain said. "If everything feels fine, I think we can play it from there."
Cain is due for some improved luck. He missed most of last season with a right flexor strain and elbow nerve irritation and finished 2-4 with a 5.79 ERA in 13 games (11 starts). He pitched five shutout innings against Colorado in his final outing of the season, generating hope for this year. Currently the longest-tenured Giant with 10 years and 38 days of service time, Cain has won 97 games, ranking sixth on the franchise's San Francisco-era list. Injuries limited him to four wins in the previous two seasons. Formerly a cinch to pitch at least 200 innings, which he did for six consecutive seasons, Cain hasn't reached that level since 2012.
All together now: Opening Day outfield to play Wednesday
The Giants will take a step toward forming their 2016 identity when the projected starting outfield will be in the lineup for the first time in Wednesday's exhibition game against the Seattle Mariners.
Left fielder Angel Pagan was the only outfield regular to participate in Monday's 10-3 Cactus League loss to Oakland. Against the Mariners, following Tuesday's scheduled off-day, he'll be joined by center fielder Denard Span and right fielder Hunter Pence.
Span has served as a designated hitter in seven games but hasn't played defensively. Pence has appeared in two games, reflecting Bochy's intent to, in his words, "slow-play" his regulars until the April 4 regular-season opener at Milwaukee draws closer.