Every spring, MLBPA chief Tony Clark travels around Florida and Arizona, visiting with all 30 major-league teams. He travels to learn of concerns and ideas from major-league players, and to communicate matters of importance. Clark also makes himself available to beat writers following major-league clubs.

In the spring of 2015, as collective bargaining talks loomed, I was in Bradenton, Florida, covering the Pirates. When Clark arrived at Pirates camp, I asked him if what players once considered a nonstarter, a salary cap — one that would guarantee a 50-50 revenue split — had become more palatable.

I asked him if any player that spring had expressed concern regarding the owners’ share of revenues, which has continued to increase over the last two decades. The trend has gained some attention in recent years at multiple media outlets.

“You’re the first person to ask,” Clark said.

I asked several union reps early that season whether there was interest in guaranteeing a split of revenues, which in 2015 and 2016 would have added tens, if not hundreds, of millions of additional dollars more into players’ bank accounts. But as we saw with the new CBA deal reached earlier this offseason, players and the union ostensibly seem most interested in protecting a player’s maximum earning potential.

Said former Detroit Tigers union rep Alex Avila: “When players hear ‘salary cap,’ to them it sounds like a limit.” Some players to whom I presented the idea of a revenue-sharing cap worried about adding framework that could be detrimental to players should careers begin to lengthen or revenue shares swings back into players’ favor.

But while the top earners among MLB players continue to do very well and while the average salary is at a record high, baseball’s middle class – in particular its lower middle class – is shrinking.

Beyond changes made to the qualifying offer, the new CBA does little to help the type of veteran free agent that remains unsigned as the opening of spring training draws nearer. The new CBA does little to address players’ lessened share of revenues. It does little to address productive players in their pre-arb years who feel underpaid.

For the purposes of this piece, I defined as “wealthy” those players earning at least three times the average player salary for that year. I considered the “minimum” earners to be compensated within 10% of the league minimum to cover most players with pre-arbitration status. All other players I combined into the “middle class” group, I used USA Today’s salary database of Opening Day payrolls as the research source. Sean Dolinar created these aesthetically pleasing charts.

In 1995, 147 players opened on MLB rosters at or near the league minimum salary. In 2006, the number had increased to 241. Last season? That number jumped to 333.

I also defined a “lower middle” group – those making up to twice the league minimum – which has been particularly encroached upon by the increased number of players being paid league minimum or something close to it.

A number of factors are conspiring against players’ revenue share and the lower-middle class of player.

Since PED testing began in 2004, player age is trending younger. There have been hundreds of fewer seasons from 30-somethings. The average hitter’s and pitcher’s age was 28.8 years in 2006. Last season, the average ages had declined to 28.4 and 28.3, respectively. (In 2001, the average batter age was 29.1 years; the average pitcher age, 28.7.) Teams have also become less interested in paying the veteran, mid-tier player when similar production is available from a pre-arbitration asset.

While there’s a luxury tax included in baseball’s CBA on certain payroll thresholds, there are no mechanisms forcing teams to meet payroll floors. The disparities between MLB revenue growth and players’ salary growth have held relatively steady since the turn of the century.

From 2003 to -16, MLB revenues have grown by 144% while player salaries have grown 84%.

Since 2003, MLB revenues have generally beat player salary growth by percentage year to year:

An embattled, endangered middle class is not unique to baseball. FiveThirtyEight found most Americans are no longer middle class.

While players are not in need of charity or tip jars and while the average salary exceeds $4 million, the application of something like the NBA’ soft cap-and-floor system to baseball, players would significantly increase their earnings.

This is what I found for Trib Total Media in 2015:

Using the NBA’s model, (if MLB) had instituted a salary cap-and-floor system for this season, 19 teams would have opened under the salary floor by a combined total of $413.5 million in payroll.

On March 11, 2016, about a year after I spoke with Clark, David Freese was interviewed in the same area of the McKechnie Field media workroom in Bradenton..

Freese seemed relieved to have found work. He had just signed a one-year, $3 million deal with the Pirates. Weeks earlier, he watched from his St. Louis home in February as full-squad workouts began. He became anxious as MLB Network began to broadcast highlights of exhibition games in early March and he remained unsigned. This was a former World Series MVP. This was a third baseman with a career 115 wRC+ mark. A year earlier, he had posted a 110 wRC+ with the Angels in 121 games. This was a middle-class ballplayer. But he was also the type of player for whom the industry increasingly did not want to pay.

Freese was 32. He was above league average, but not significantly so. He was the type of player, producing the type of numbers, teams would rather compensate near the league minimum. And after a strong first half in 2016, rather than test the open market in an industry that generated nearly $10 billion in revenue last season, Freese elected to sign a modest two-year extension. After the deal was announced, he told the media gathered before his locker, that his experience, his wait, the previous offseason had played a role in his decision. He didn’t want to be sitting at home in March again.

Said Freese to Yahoo! national baseball scribe Tim Brown last spring:

“The game’s definitely getting younger. Me personally, that felt like that this [2015-16] offseason. You sit back and, ‘Wow, this game got young.’ And I get it. I understand, they’re pushing prospects.”

Teams will pay for quality in free agency – there have been 53 $100 million-plus contracts signed since 2007 – but there are a number of free agents still available who are likely beginning to feel what Freese experienced as last winter began to thaw.

Consider FanGraphs’ top-50 free agents of the 2016-17 offseason. The top 19 free agents have all reached agreements this offseason. But note the amount of players ranked between 21-50, let alone those free agents not ranked, who are still looking for work less than a month before camps open.

The middle class of ballplayer, the Freeses of the sport, are perhaps becoming endangered.

There’s no mechanism forcing teams to spend. There’s no tax or penalty on low-end payrolls. There’s little reason for the game to halt its trend of becoming younger.

While teams are perhaps operating logically and rationally, is the union? Or is the union too concerned with the upper 10% of its constituency? While many fans care little for squabbles between billionaires and millionaires, these trends could eventually set the stage for a larger labor fight, which could threaten something about which fans care deeply: labor peace.