TORONTO — Spring training stats don’t matter. At all.

But digging deeper than what the small-sample-size results say in the box scores during meaningless games against diluted competition, physical changes and process adjustments can matter. A lot.

With the Jays wrapping up their slate of 28 pretend Grapefruit League games on Monday, a largely positive month of March has ended on a bit of a down note, with a number of key — albeit not likely to be long-term — injuries throwing the opening day roster configuration into flux.

Aside from Hyun-Jin Ryu getting the ball opening day on Thursday in the Bronx and the offence expected to do a lot of the heavy lifting, there are intriguing big-picture questions all over the roster that will take time to answer over the first couple months of the regular season.

With the focus now shifting from preparation to winning baseball games, here are five things that matter from spring training games in Florida this month.

1. Marcus Semien looks like a plus 2B

A good shortstop making the transition to second base usually works out well.

It works out even better when the player is all-in on the move and has a work ethic like the one the 30-year-old Semien possesses.

From day one of camp, Semien and shortstop Bo Bichette have made it a point to develop chemistry up the middle, with turning the double play at the top of the list.

While it’s mostly based on the eye test and Semien looking comfortable at a position he hasn’t played since 2014 with the Chicago White Sox, Semien has turned eight double plays and made only one error in 16 starts at his new position, looking right at home in the process.

The bat is still going to be key to the one-year, $18-million contract working out for the Jays — the right-handed hitter has swatted three homers while mostly hitting out of the two-hole in manager Charlie Montoyo’s lineup — but Semien already looks like he could be a plus defender at the keystone and a big upgrade defensively on Cavan Biggio’s so-so glove (minus-2 Outs Above Average in 2020) at the position.

Notably, Biggio has also looked good at third base this spring, making that shift looking like a win-win, even if the sample size is still too tiny to really judge.

2. Kirby Yates’ season-ending injury

He was supposed to give the Jays a proven arm at the back end of Montoyo’s bullpen, allowing the rest of the relief arms to fall into place ahead of the 34-year-old lynchpin.

That dream died after two spring appearances, as the elbow issues that ended Yates’ 2020 season reappeared and the veteran decided the time was right to undergo the second Tommy John surgery of his career.

The Blue Jays knew this was a possibility when they signed him in January, reworking his contract to turn some of the guaranteed money into incentives.

In the end, the Jays will still pay him $5.5 million to provide nothing in 2021, and it’s a contract that will be remembered for all the wrong reasons, even if the idea of chasing Yates’ extreme upside was the right one.

It leaves the Jays back in the same spot they were last August after Ken Giles went down in similar fashion, and puts more pressure on Jordan Romano, Rafael Dolis, David Phelps, Tyler Chatwood and Ryan Borucki in high-leverage spots.

3. Robbie Ray’s velocity (and injury)

The 29-year-old lefty was one of the early bright spots in camp, showing improved command, both in terms of walk rate and pitches in the zone through four spring starts.

Without question, that’s the key to Ray’s season and a potential resurgence. Sporting a 4.3 BB/9 over his seven seasons, Ray is never going to be a control artist, but his ability to get strikeouts (11.1 K/9) mitigates that to some extent.

But his walk rate ballooned in 2020, as he issued free passes to 45 batters over 51.2 innings, a rate that only marginally improved when he was dealt from Arizona to the Jays at the trade deadline.

The Jays, however, liked enough of what they saw to quickly re-sign Ray early in free agency in November to an $8 million deal for 2021, giving him another chance to work with pitching coach Pete Walker and implement further changes.

March numbers don’t matter. We’ve seen good spring performances before from Ray, including 32 strikeouts and just eight walks across 16.1 innings in 2019.

Still, through 13.2 frames this spring, Ray struck out 18 and walked just five, but even more importantly, he was showing cleaner mechanics that led to increased velocity.

In what would be his final spring outing on March 19, Ray was touching 98 mph and hovering in the 96-mph range via Statcast, punching out seven and walking just one against the Detroit Tigers.

The problem is Ray fell down some stairs at his Dunedin rental while carrying his kid last week and suffered a bruise to his pitching elbow, leaving him unavailable to start the season.

Montoyo said he’ll miss at least one turn through the rotation, and he could land on the 10-day IL this week.

The Jays’ fingers are crossed that he returns showing the same type of stuff and command.

4. Alejandro Kirk’s progress on defence

Called up in an emergency last September when the Jays were getting nothing offensively from the catcher spot, Kirk proved his bat is capable of not only handling major-league arms but excelling against them.

The 22-year-old Mexican has hit at every single level throughout his short professional career, a trend that has continued this spring.

On Sunday, Montoyo confirmed the inevitable: Kirk will be the backup catcher to Danny Jansen to start the season Thursday in New York.

Not really a surprise. It’s something that should benefit both parties, as it allows Kirk to start out catching a couple times a week, while also playing a role as a key late-game pinch-hitter and DH option.

His bat may force its way into the lineup more and more as the season goes on, but the Jays will let that play out naturally and Jansen’s performance at the plate will help dictate that.

While Kirk continuing to show a special ability to barrel up baseballs was not a surprise, he was also able to show some incremental defensive improvements this spring.

He lost a little bit of weight in the winter and was moving better behind the plate. Built like a fire hydrant on roller skates, Kirk is never going to be known as a defensive catcher, but if he can move well enough to block baseballs in the dirt and not give away runs, he only needs to be acceptable back there to provide value.

The biggest thing to watch this season will be how Kirk controls the running game, as teams were a perfect 4-of-4 in steals against him in his 52 innings behind the plate in 2020.

Even with the strides he made this spring, he’ll have to continue to get better in all areas with the glove.

5. Tim Mayza’s filthy sinker

While the Yates injury moved the five aforementioned bullpen names up in the pecking order, it also opened doors for others to climb onto the roster.

In his return from Tommy John surgery, Mayza’s spring could not be ignored, and the 29-year-old southpaw was informed Sunday that he’s made the opening day roster.

In camp on a minor-league deal, the odds were stacked against the lefty to begin camp, but over the past two weeks it became apparent that the stuff was better than ever and it didn’t matter that he could be stashed at the alternate site or on the taxi squad to begin the year without the risk of losing him.

It may not have jumped out that Mayza allowed just one hit across his 6.2 frames, but the way his sinker has looked sure has.

The pitch was ticking up into the 95-mph range and one person even described it as “Zack Britton-esque.”

With the offering already holding hitters to a .169 batting average and a .277 slugging percentage pre arm injury in 2019, it’s looked like an elite pitch this spring and helps add some important depth to the Jays’ bullpen.

There’s a real chance Borucki and Mayza could be a dominant 1-2 lefty punch for Montoyo, something the Jays haven’t had in a long time.​