TORONTO — Vladimir Guerrero Jr.'s time toiling in minor-league cities is over. Next stop: Toronto.

Blue Jays manager Charlie Montoyo announced after Toronto's 4-0 loss to the San Francisco Giants on Wednesday that Guerrero, baseball's top prospect, would join the big league team Friday to make his MLB debut against the Oakland Athletics.

The much anticipated announcement followed another stellar performance from Guerrero with the triple-A Buffalo Bisons, where he went 2-for-5 with a home run in a game that started before noon ET.

"It's a big moment for the Toronto Blue Jays," Montoyo said. "He's the No. 1 prospect in baseball and he's coming on Friday so it's a big moment for us.

"Hopefully he becomes what everybody thinks he's going to become and that's going to be good for all of us — for the city of Toronto, the Blue Jays, the organization."

Wednesday marked the first time Guerrero had played three games in as many days for Buffalo since suffering an oblique injury in spring training last month.

Batting third as the designated hitter, Guerrero hit the go-ahead home run in the seventh, as the Bisons beat the Syracuse Mets 5-4.

The 20-year-old said after the game he didn't know when he'll be called up. Montoyo said he wanted to let Bisons manager Bobby Meacham to deliver the news, which he expected would happen Wednesday night. Toronto is off on Thursday and will open a three-game series with Oakland on Friday at Rogers Centre.

"I'll talk to him when he gets here," Montoyo said. "It's Bobby Meacham's (role) and Gil Kim's (Toronto's Director of Player Development) to give him the good news, just like I used to do when I was (managing) in triple-A. I wouldn't take that moment away from them."

As for Montoyo's message for Guerrero when he does arrive, the Jays rookie manager said he'll tell him to "just relax and play."

"Just like I told him in spring training: 'Do you best.' And he will."

Teammate Clay Buchholz, whose first hit surrendered in the major leagues was to Guerrero's Hall of Fame father in 2007, said he was excited to see what Guerrero could do at the game's top level.

"I actually pitched to him a couple times (while both were rehabbing injuries in Florida after spring training) and he hit a really hard ball off me," Buchholz said with a laugh. "So yeah, I think it's going to be good."

Added the veteran right-hander: "It's pretty neat to be around the son of the guy that got the first hit off me in the big leagues. I think everybody's looking forward to it."

Bisons hitting coach Corey Hart and Meacham both said earlier Wednesday that Guerrero was ready for the big leagues because of his baseball intelligence and inquisitive nature.

"Is he good enough to play at the big level? Yes," Meacham said. "He was two years ago. But you can't develop really at the big level when you're that young and you're still learning that many things."

Meacham said the way Guerrero thinks about the entire game is more advanced than the average player his age.

He watches not only his own at-bats and what the pitchers are throwing, but how the catcher calls the game. Meacham said Guerrero knows how to set a pitcher up — if a curveball strikes him out early in the game, he's waiting for it later.

"I think it came from playing with older guys that I learn from all the time," Guererro said through a translator. "And just learning from them and watching them ... play. I got it from kind of following their footsteps."

Guerrero — born in Montreal when his father played for the Expos and raised in the Dominican Republic — was batting .367 with three homers and eight RBIs in eight games with Buffalo this season.

A smile spread across Montoyo's face before Toronto's game when he was told about Guerrero's latest home run.

"I think we have to be patient, but I honestly think he's going to do well," Montoyo said. "He's comfortable, he's not going to be nervous or scared about the big leagues."

— with files from Josh Schafer in Syracuse, N.Y.