OAKLAND -- Last September, Lawrence Butler was finishing a second consecutive season in High-A ball. The encouraging numbers helped him vault up the A’s prospect radar, but there was still an obvious mountain left for him to climb to rise through the system.

A year later, Butler is a big leaguer, and he’s thriving. Playing just his 23rd Major League game in Monday’s 6-5 loss to the Blue Jays in 10 innings at the Coliseum, the 23-year-old outfielder notched his first career multihomer game. Butler, Oakland's No. 4 prospect per MLB Pipeline, got the A’s on the board in the fifth with a solo shot and later inched them to within a run of tying the game in the 10th with a two-run blast.

“Coming from High-A and hitting two home runs in a big league game in less than a year’s time is pretty impressive,” manager Mark Kotsay said. “This is a high school Draft kid that has taken time to mature. But you’re seeing that maturation process right now, happening at the big league level. The success he’s having is a result of the work he put in this offseason. … To see his success, it’s a great sign.”

Neither homer -- which combined to travel a Statcast-projected 820 feet -- came off run-of-the-mill Major League pitchers.

Butler jumped on a first-pitch curveball from two-time All-Star José Berríos and sent it to straightaway center an estimated 417 feet for his first homer of the day. His second was a 403-foot blast to right-center off another two-time All-Star in Blue Jays closer Jordan Romano that came off Butler’s bat at an impressive 110.5 mph.

The homer was just the fifth Romano had allowed in 49 2/3 innings this season.

“That’s another thing you dream about as a kid, hitting two home runs in the big leagues,” Butler said. “To do it twice against two really good pitchers, that’s pretty cool.”

After homering once in his first 18 games, Butler has tapped into his power as of late, with three long balls in five games. All four of his homers have traveled more than 400 feet.

Of course, power is only one of a handful of tools that make Butler such a tantalizing talent. There is also a speed element to his game that has yet to show up at the big league level.

“I can’t tell you what [Butler's] ceiling is, but I think he’s only going to get better,” Kotsay said. “He has the tools to play at a really high level as an impact player. I don’t think we’ve seen the best of him. This kid is really young and exciting.”

Even though the A’s came up short on Monday to snap a three-game winning streak, the loss to a playoff-contending Blue Jays squad still provided a glimpse of the better days ahead that they believe to be on the horizon. In addition to Butler, fellow rookies Jordan Diaz and Ryan Noda also launched solo home runs. Zack Gelof, August’s American League Rookie of the Month, swiped his 10th base, becoming just the sixth rookie in franchise history with 10 homers and 10 steals in a season and the first since Yoenis Céspedes in 2012.

On the pitching side, rookie reliever Lucas Erceg held down Toronto’s offense in a tie game with scoreless eighth and ninth innings.

“The A’s have a really bright future,” Butler said. “People might think of us as the laughingstock of the league this year, but next year is going to be a whole different story.”

Butler added: “I really want us to go out with a winning record. Play good ball the rest of the way, win some games and put the league on notice that we’re not the same team we were at the beginning of the year.”