HOUSTON — As he’s battled thumb issues off and on since 2023, Max Scherzer’s grown very familiar with the anatomy of his pollex — or digitus primus manus if you prefer.

The CMC and MCP joints; the radial collateral ligament; the extensor pollicis longus and extensor pollicis brevis. Turns out there’s a lot going on in that digit.

And so, as he leaned on a clubhouse wall at Kaiken Field on Monday and sought to explain the latest developments in his ongoing odyssey of thumb issues, Scherzer opted to keep it simple.

“You have three joints in your thumb — joint one, joint two, and joint three,” Scherzer said, referring to, in order, the joint closest to his finger nail, the joint lateral to his knuckles, and the joint near his wrist. “I got [a cortisone shot] in joint two. And when I was starting to play catch again after that, joint one started to hurt. We were kind of thinking that was going to subside. It just never did.”

That’s why, last week, Scherzer returned to one of the several hand specialists he’s been consulting on this matter and received a second cortisone shot in joint one, following the original shot in joint two at the end of March.

“It’s just tough,” Scherzer said. “Once I got the shot in joint two, then joint one and that tendon on top was barking. It wasn’t allowing me to progress in a throwing program. It was only going to get worse. So, we had to address that.”

Will this be the end of the shots for Scherzer and the beginning of his return to the mound? Your guess is as good as anyone’s. Scherzer’s been down this road before. He’s believed the issue is resolved only for it to come up again. He’s made several positive strides in a ramp-up only to aggravate the injury once more. Progress and setbacks, progress and setbacks.

“Last September, I took a shot in joint three. And then in October, I had to have a shot in joint two,” Scherzer said. “So, that time was three to two. This time has been two to one. So, who knows? Maybe I’ll need another shot in joint three. I don’t know. I don’t have the answers. I don’t know how to solve this.”

For now, this situation is the definition of day-to-day. After throwing from flat ground in left field at Daikin Park on Monday afternoon, Scherzer said his thumb felt the best it has in a while. He could get a good squeeze on the ball without discomfort and grip his secondary pitches properly. That wasn’t the case last week.

Still, Scherzer stopped short of saying it was a particularly good day, describing it instead as “OK for day one.”

“I just recognize that I’m not out of the woods on this,” Scherzer said. “Until I’m throwing in games, until I’m at 75 pitches, I am not out of the woods on this. … There is still a very long road in front of me to get back.”

Considering its been three weeks since he’s pitched, Scherzer’s essentially arrived back at square one of spring training. Once his thumb is feeling good enough to get back to throwing from a mound, he’ll need to deliberately rebuild arm strength and endurance, progressively increasing pitch volume over time. In short — Scherzer isn’t particularly close to a return.

Meanwhile, the Blue Jays will need to continue seeking backfills for his rotation spot, an opening Easton Lucas was excelling in until he wasn’t. After throwing 10.1 scoreless innings across his first two starts in Scherzer’s place, striking out 11 while walking only three in the process, Lucas allowed 14 runs over 6.2 innings in his next two outings, surrendering five home runs.

Monday, the Blue Jays optioned Lucas to triple-A Buffalo, recalling left-handed reliever Josh Walker for bullpen coverage required in part due to Lucas’s struggles. And rather than seek an alternative option for when the club’s fifth starter spot comes up again this weekend in New York, the Blue Jays will instead opt to leverage Thursday’s off day and keep the first four in the club’s rotation on regular rest.

That means after Jose Berrios opens this weekend’s series vs the Yankees, Kevin Gausman and Chris Bassitt will follow. It robs two starters in their mid-30s of an extra day’s rest between outings, something that’s benefitted their results in the past. It also adds workload to their arms early in a six-month marathon with a 22-games-in-23-days stretch looming on the horizon from late May through early June.

That isn’t ideal, but it also isn’t the first time we’ve seen the Blue Jays do this as they’ve opted to use a four-man rotation or frequent bullpen days at times over each of the last two seasons when lacking a viable alternative to join the starting staff. An off day on Monday ahead of a six-game homestand beginning next week lightens the load this time around. But it still isn’t something the Blue Jays want to make a habit of.

That’s why the club’s plan is only to use this four-man rotation for one turn before returning to a five-starter configuration during that upcoming homestand. Considering how important strong starting pitching is for a team currently averaging fewer than four runs per game, and the fact Bowden Francis (turning 29 on Tuesday) and Jose Berrios (31 next month) represent the “youth” in that rotation, the Blue Jays don’t want to test anyone’s limits this early in the season.

“I think they’re all in a good spot right now,” Blue Jays manager John Schneider said of his four current starters. “The hope is that it’s one time through the rotation and then we’ll get back on a five day. But they’re all good with it. They’re all in good spots.”