For a brief time in baseball history, June was the month of “un-retirement.”

In 2006, the Houston Astros were 37-35 when pitcher Roger Clemens came out of retirement and made his season debut on June 22 against the Minnesota Twins. He made 18 more starts for the Astros that year, pitched no fewer than five innings in each, and went 7-6 with a 2.30 ERA.

In 2007, the New York Yankees were 28-31 when Clemens un-retired again, debuting on June 9 against the Pittsburgh Pirates. He made another 17 regular-season starts that year, going 6-6 with a 4.14 ERA, plus an ill-fated start in the American League Division Series. By February 2012, when Roy Oswalt was contemplating his future after 11 seasons as one of the best pitchers in baseball, Clemens’ precedent had become canon.

“After waiting until spring training and failing to land a job to his satisfaction,” ESPN reported, “free agent pitcher Roy Oswalt has told major league clubs that he might pull a Roger Clemens and return midseason, according to a baseball source.”

On May 30, Oswalt signed with the Texas Rangers. He debuted on June 22 and finished out the season with the Rangers. The delayed beginning did not portend a strong ending. Six inconsistent starts left Oswalt with a 6.49 ERA, and he finished the season in the bullpen. After back-to-back World Series appearances, the Rangers were eliminated in the American League wild-card game.

The brief run of veteran pitcher un-retirements did not become a trend (notwithstanding Cole Hamels’ ill-fated comeback with the Dodgers in 2021). What did become a trend was something superficially similar. Clemens pitched 113 1/3 innings in 2006 and 99 innings in 2007. The number of starting-pitcher seasons between 99 and 114 innings reached its peak last season, at 13.

Teams shuffle more pitchers in and out of their active roster at midseason now than in any previous era. The Angels have already used 26 different pitchers in 2023 — one more than they used during the entire 2015 season. That’s because “load management” has become a science, leading teams to suppress starting pitchers’ workloads into the mini-seasons they are today, while using a larger pitching staff to spread the load around.

If anything, the present era seems more rife for a veteran pitcher to come out of retirement or, more accurately, delay the start of his season with an eye toward helping a contending team conquer October.

So, why hasn’t this trend materialized?

Speaking on background, baseball industry sources painted a broad picture that suggests the trend did materialize — just not in the way Clemens and Oswalt modeled it. They agreed on a few main points that help answer the question:

1. Clemens is an outlier

Clemens, who won 354 games in his 24-year career, retired and un-retired several times after the age of 40. After the first four instances, he was able to land a major league contract. You’d be hard-pressed to find a similar pitcher during his era, let alone now.

Only three starters — Rich Hill, Adam Wainwright and Justin Verlander — began pitching this season at age 40 or older. Only Zack Greinke and Charlie Morton (among current major league starters) can join the group next year.

Let’s assume one team would be willing to sign any one of those pitchers two months into the 2024 season. It’s anything but a given that their motivations would align. Nor is it safe, sources said, to assume Clemens (or Oswalt) were motivated to limit their innings in order to maximize their October performance — the present-day imperative driving the trend toward larger pitching staffs.

Regardless, if Clemens’ combination of stature and ability is what allowed him to skip the first two months of a season — not once, but twice — there’s no guarantee any pitcher can do it again.

2. Why train on your own?

When a free agent signs with a team in the offseason, it provides his family, his front office, and his teammates with a degree of certainty. Remaining a free agent into the season rarely happens for a reason. All other factors being equal, players and teams prefer to have contracts settled before spring training camps open.

What happens once spring training camps open has changed a lot since Clemens’ and Oswalt’s day. The average major league team’s facilities and their associated training staffs (strength and conditioning, medical, performance science, mental skills, etc.) are well-oiled machines, difficult to compile (and afford) in the wild.

A pitcher can gain a lot by working out at a high-end independent training facility that regularly collaborates with major league organizations. It’s not not an option, but the relative scarcity of these facilities is another reason why players prefer to report to spring training on time.

3. The shape of “load management”

For all the reasons listed above (and more), teams are more willing to accept the uncertainty that comes with signing pitchers whose durability is a question mark. Can’t pitch for the first month or two of a season? Fine. We’ll send you to our facility and help you get back as soon as possible.

Verlander, who missed the first month of the 2023 season, is a relevant example. So is the Dodgers’ spring training facility, where veterans Jimmy Nelson, Daniel Hudson and Alex Reyes have been earning the bulk of their salaries. These are examples of the prevailing “load management” strategy in action.

In that vein, by limiting a pitcher’s number of starts and/or innings per start, teams are essentially achieving the same effect as having him throw five or more innings every fifth day from the beginning of June. Even the every-fifth-day mantra is going out the window.

“I don’t know if six-man rotations are coming next year,” one agent told me, “but they’re coming.”

What’s lost in these strategies is the fun of it all. Imagine if you’re a team hovering around .500 and a future Hall of Fame pitcher is sitting at home, just waiting for your GM to call. For fans, knowing that pitcher took the call is a shot in the arm — another reason to hope, another reason to tune in every fifth day.

The Texas Rangers overpaid for Jacob deGrom knowing he would never start five full seasons’ worth of games; this week, they learned deGrom would need Tommy John surgery and not return until 2024. This is the opposite of a fan’s definition of fun: rising at the anticipation of seeing a star player pitch, sinking at his inevitable trip to the injured list.

But it’s how the Clemens/Oswalt strategy works these days.