TORONTO --- About 20 minutes before first pitch Friday night at Rogers Centre, Teoscar Hernandez jogged out of the visitors' dugout and on to the field to stretch.

Yet another prospect had arrived to the Astros.

Soon after donning his grey No. 35 uniform, Hernandez made his major league debut in the Astros' series opener against the Blue Jays. Versatile enough to play any of the three outfield positions, he started in center and batted eighth in only his 39th game above Class AA ball.

"Like any young player," manager A.J. Hinch said, "I want to get him acclimated as fast as possible and see what he can offer."

Hernandez, who did not arrive from Class AAA Fresno in time for batting practice and thus was not available to speak to reporters before the game, earned his promotion behind a breakout season in Class AA and Class AAA. Promoted to Fresno at the same time as top prospect Alex Bregman, Hernandez played only 38 games in the Pacific Coast League before Friday's call-up.

It marked a quick rise for the 23-year-old Dominican, who opened the season in Class AA for the second straight year. He struggled last year to the point where the Astros left him unprotected in December's Rule 5 draft. No team picked him, and from the outset of this season he appeared to put it all together.

Hernandez, an international signee of the previous Astros' front office in Feb. 2011, improved his terrible .219 average and .637 OPS from 2015 to .307 and .836 this season in the minors. He batted .315 in 144 at-bats in Class AAA before he was summoned to Toronto, where he is one of 10 rookies on the Astros' active roster.

"He really took his game up to a whole new level," general manager Jeff Luhnow said. "I think it all has to do with what we preach throughout the majors and minors – getting the right pitches to hit and making good swing decisions.

"He's getting on base at a much higher rate than he ever has and as a result pitchers are having to come into his zone and he's able to drive the ball. We hope that continues up here. Sometimes players get up here and panic a little bit and expand their zone and change their decisions. But if he maintains that he'll be a very successful major league player."