SAN FRANCISCO -- The momentum that center fielder Steven Duggar generated for the Giants ground to an abrupt halt Wednesday when the ballclub placed him on the 10-day disabled list with a bruised left shoulder, which was later found to include a torn labrum.
Giants manager Bruce Bochy said after the evening's 3-1 loss to Arizona that the team's medical staff recommended surgery for Duggar. Bochy added that if Duggar undergoes surgery, "he'd be ready to start the [2019] season."
To fill Duggar's place on the roster, the Giants selected veteran outfielder Gregor Blanco from Triple-A Sacramento. San Francisco moved catcher Buster Posey to the 60-day DL to accommodate Blanco on the 40-man roster.
The hope that Duggar brought and the promise that he displayed won't be replaced by any transaction, however. His gradual improvement since he made his Major League debut July 8 accelerated so much recently that he almost single-handedly dragged the Giants back to the fringes of the race for postseason berths.
"As well as he was playing, he was absolutely igniting us at times," Bochy said. "I feel for the kid. He really was in a good place, as far as his confidence and his swing."
Sunday, Duggar's two-run triple made the difference in a 3-1 victory over Texas.
Monday, his two-run homer accounted for all the scoring as San Francisco outlasted Arizona.
Tuesday, he assisted on a critical out at home plate and scored the game's lone run as the Giants lengthened their winning streak to four.

Duggar sustained his fateful injury moments before he crossed home plate. After drawing a ninth-inning walk, he took a big turn around second base on Nick Hundley's single and was forced to scramble back to the bag. Duggar said he initially felt pain when he was tagged. He added that his shoulder slipped out of its socket, then settled back in on its own.
During brief remarks to reporters Wednesday before his assignment to the DL was announced, Duggar said his range of motion "wasn't horrible" but acknowledged he felt as if he had a "dead arm." After meeting with Duggar, Bochy said the 24-year-old felt "pretty sore."

Injuries also ruined Duggar's 2017 season. He missed the first six weeks with a flexor tendon strain in his right elbow, then strained his left hamstring June 30.
Renowned for his speed, Duggar owns a .255/.303/.390 slash line in 41 games with the Giants.

He became the latest key performer to be sidelined at some juncture during this season, joining Posey; starting pitchers Madison Bumgarner, Johnny Cueto, Jeff Samardzija and Dereck Rodriguez; relievers Mark Melancon and Hunter Strickland; outfielders Hunter Pence and Mac Williamson; and infielders Brandon Belt, Joe Panik and Evan Longoria.
Blanco, 34, endeared himself to Giants fans during his first tour of duty with the club, which lasted from 2012-16. He made San Francisco's Opening Day roster this year as a non-roster invitee to Spring Training but was designated for assignment June 2 when Pence was activated from the disabled list. Blanco hit .242 in 42 games with the Giants before batting .247 in 60 games for Sacramento.
Tuesday, Blanco delivered a victory for the River Cats with a walk-off homer.
"That's what gets you up here," Bochy said, mustering humor.
• Samardzija received a second opinion on his ailing shoulder from Dr. Tim McAdams, who echoed the previous recommendations of rest for the right-hander.
"He didn't find anything structurally wrong," Bochy said.