A strong pitching performance from rookies Thomas Hatch and Anthony Kay in Sunday’s series finale was overshadowed by a late injury to closer Ken Giles, as the Blue Jays gave up their late lead and lost, 6-5, to the Rays in 10 innings.

Toronto turned to Hatch for his MLB debut after the club's No. 23 prospect had been called “quietly electric” by pitching coach Pete Walker in Summer Camp. Hatch's presence is a little louder now, as he touched 96 mph and struck out three over 2 1/3 innings before handing off to the lefty Kay for the piggyback.

The zip on Hatch’s fastball surprised, but his changeup was as good as advertised. By varying 9-10 mph between his heater and change, Hatch was able to keep the Rays off balance at times, earning three swings-and-misses with each pitch.

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“I think the best thing I can take away from it is that everything translates to this level,” Hatch said. “Sometimes there’s that doubt going from Minor League ball to the big leagues, but I was confident. Even getting my feet wet this spring facing big league hitters was a big step in realizing I can get these guys out.”

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This rotation spot belongs to No. 1 prospect Nate Pearson long term, potentially as early as the next trip through the rotation, but Hatch and Kay patched it over better than the Blue Jays could have hoped. As Toronto heads off to Washington, here’s three things we learned on the opening weekend against the Rays.

1) The bullpen needs balance ... and maybe a closer
Nothing makes a manager look smarter than a good bullpen. On Opening Day, Montoyo called the names he’s been waiting to call for months in Jordan Romano, Anthony Bass, Rafael Dolis and eventually Giles. It worked that day, then backfired in Game 2, when Montoyo was forced to turn to Sam Gaviglio in a tied game in the eighth.

The true loss during Sunday's Game 3 was Giles, who was removed with right elbow soreness. Bass, Romano and Dolis were used again too, though, and Montoyo will need to balance those relievers so that the Blue Jays aren’t caught without them in a group again. Beginning Monday, it’s possible that some of them -- Romano especially, after throwing just nine pitches -- could go on back-to-back days.

In a 60-game season, most innings are high-leverage innings.

2) It’s time to get aggressive
Montoyo used three lineups in three days. To some extent, this is to be expected as the Blue Jays faced a lefty in Blake Snell and Toronto decided that Lourdes Gurriel Jr. was not ready to play two games in two days this early, though Gurriel eventually pinch-hit for Anthony Alford and remained in the game. Going forward, though, how prevalent will these day-to-day changes be?

“I’m going to say pretty lose to the same lineup,” Montoyo said Sunday, which would represent a significant shift from 2019 and the opening series of 2020.

These decisions, much like Montoyo’s bullpen decisions, will be under the microscope in what is essentially a playoff race out of the gates. It’s important to keep bench players fresh and spread the reps around over 162 games, but over 60, the Blue Jays’ best players need to be in the lineup as often as possible.

3) Vladdy’s still the key
The young core of Bo Bichette, Cavan Biggio and Vladimir Guerrero Jr. had its moments in the opening series, particularly Biggio, who changed the opener with a bunt single and put it away with a three-run home run. A heady hitter with a feel for when to be aggressive, this could be a big season for Biggio.

Bichette will hit, and his style is well-suited to the sprint style of a 60-game season, but Guerrero might be the variable of the group. On one hand, the 21-year-old star has collected hits in all three games so far, including two on Sunday. On the other hand, there was still plenty of ground-ball contact. Guerrero is working on his swing and continuing to work on his body, which remains a major factor in his success.

“He can always improve,” Montoyo said. “I know he’s going to be all right; he’s just a young kid. That’s what I would say. There’s always room for improvement there.”