LOS ANGELES -- In a World Series matchup loaded with storylines, one was seemingly put to rest Thursday: Los Angeles Dodgers star Shohei Ohtani will not make a dramatic return to the mound to face the New York Yankees.

"There is no possibility, none whatsoever," Dodgers manager Dave Roberts said. "Thank you for asking."

Ohtani has not pitched since undergoing major elbow surgery last September while with the Los Angeles Angels. The two-way star was strictly a designated hitter for the Dodgers this season, one so good that he is the overwhelming favorite to win NL MVP after posting the first 50/50 season in MLB history.

All the while, he rehabbed his elbow. Finally, in late August, he began throwing off a mound. Then, last month, Roberts opened the door to Ohtani pitching in the postseason. Soon, however, the Dodgers put the brakes on the idea. Roberts on Thursday slammed them.

Ohtani, meanwhile, did not appear disappointed with the decision.

"I've never said to them that I wanted to pitch in the postseason," Ohtani said through an interpreter.

Ohtani would've joined a bullpen that has been foundational in the Dodgers' postseason success. With just three starters, the Dodgers are expected to deploy at least one bullpen game in the World Series. The relief corps could receive reinforcements.

Alex Vesia, the Dodgers' top left-handed reliever, told ESPN's Alden González that he is "90% sure" he will be on the Dodgers' roster after missing the National League Championship Series with an intercostal injury. Vesia threw 15 pitches in a live bullpen session Wednesday. He tossed three scoreless innings in the NL Division Series against the San Diego Padres after recording a 1.76 ERA in 67 appearances during the regular season.

Additionally, Roberts said Brusdar Graterol is also "trending in the right direction." Graterol missed most of the regular season with shoulder and hamstring injuries, appearing in just seven games. The right-hander has a 1.64 ERA in 22 career postseason games.

"It's part of the math," Roberts said of Graterol's limited action this season. "I think the other part is his track record in the postseason, how good he's been, how good the heartbeat's been. We believe in the person, the stuff.

"So then if it plays out as he's on the roster, then it's more of a decision on when I feel comfortable using him. I just don't know that answer, but I am hopeful that he's in a good spot right now."

ESPN's Alden González contributed to this report.