TORONTO — The rise and fall of Yoan Moncada took nine days.

Moncada joined the Red Sox in Oakland on Sept. 2 and was immediately named the team’s primary third baseman. The plan was for Moncada to start against righthanders with Aaron Hill facing lefthanders.

“He wouldn’t be here if we didn’t feel like he could step in and contribute,’’ manager John Farrell said at time.

Moncada was called up from Double A, where he had struck out in 36 percent of his at-bats. The 21-year-old also had limited experience at third base. But all that was brushed aside.

“We think he can help us win ballgames,’’ president of baseball operations Dave Dombrowski said when Moncada arrived. “For me, he looks ready.’’

But the Sox had it wrong. Moncada started three games and was so overmatched at the plate that Travis Shaw was put back at third base.

Moncada is 4 of 18 (.222) and has struck out 11 times. He has an active streak of eight strikeouts, one shy of the major league record for position players.

“This is a great learning experience for Yoan,’’ Farrell said Saturday before the Red Sox lost, 3-2, to the Blue Jays. “While he probably got a boost of confidence coming to the big leagues, you get challenged a little bit and got to take step back to rebuild that.

“Our primary goal is to win. Development in this situation does not take a front seat.’’

Then it got worse. Moncada pinch ran for David Ortiz with two outs in the eighth inning and retreated back to first base when Mookie Betts popped up.

The Jays caught the ball and no harm was done. But it’s a bad look for all involved that a player the Sox invested $63 million in forgot how many outs there were in a one-run game.

“That’s an elementary play, to be honest with you, at this level,’’ Farrell said. “Two outs and you’re on the move no matter what direction the ball’s going in. That’s been addressed . . . we’ve got to be better than that.’’

Said Moncada via a translator: “Just a simple confusion on my part. That’s basically it.’’

It’s not quite so simple. If Moncada can’t be trusted to pinch run, he is a player without a role. Farrell said Moncada would get “an occasional at-bat’’ over the final 21 games but otherwise watch games from the bench.

“So much can be had from watching the game at this stage of his career,’’ the manager said. “If you notice in the dugout, he’s in and around a number of guys — and that’s done on purpose — to walk through game situations and think the game, to rehearse certain things. When he finds himself back in those spots, hopefully he’s lived it at least in his mind.

“The beauty of this game is you can’t hide. That’s the one-on-one competition. Sooner or later he’ll come out of it.’’

Moncada tried to stay positive.

“It’s been a tough few games. Just working hard to get out of that slump and keep moving forward,’’ he said. “You have to have patience and learn from every situation. It’s been a tough week. It’s part of the process.’’

Benintendi on deck

With Single A Salem now out of the Carolina League playoffs, there’s nowhere for Andrew Benintendi to play an injury rehabilitation game or two. So the Red Sox will organize a simulated game at Fenway Park on Tuesday afternoon before they play the Baltimore Orioles.

“We’re going to make our own at-bats,’’ Farrell said.

The Sox will have Henry Owens and likely a few relievers pitch and get Benintendi five or six at-bats.

“Once we get through half-a-dozen at-bats at least on Tuesday, we might be a position where we could see him on the field shortly after,’’ Farrell said.

Benintendi has been out since Aug. 25 with a sprained left knee.

Fast track

Rick Porcello got to 20 wins quicker than any pitcher since Justin Verlander of the Tigers won his 20th game on Aug. 27, 2011. Verlander was 25-5 that season and won the AL MVP and Cy Young awards . . . The inflammation in Steven Wright’s sore right shoulder is subsiding but he has not started throwing. Wright has been shut down since his start on Aug. 31 . . . Dustin Pedroia’s home run in the sixth inning extended his hit streak against Toronto to 28 games. That goes back to 2014. It is the longest hit streak against Toronto in history . . . Betts has reached base safely in 27 consecutive games, the longest active streak in the AL . . . Red Sox relievers have pitched 14⅔ innings on the road trip and allowed two runs, both unearned.

Peter Abraham can be reached at pabraham@globe.com. Follow him on Twitter @PeteAbe.