Early in the season it would have been absurd to even speculate. Only this year’s Celtics, forced into frequent and dramatic lineup changes, could prompt the question. Since Monday night, though, fans are considering it. With a month left in the regular season and the Eastern Conference playoff teams virtually decided, they are looking past this season and wondering.

Is Jeff Green the future savior of the franchise?

Okay, “savior” is excessive. But even without that word the sentence is still absurd. Sure, Jeff Green will likely be a part of any success in Boston’s fast-approaching future without Kevin Garnett and Paul Pierce. But this future team, even with Rajon Rondo and Jared Sullinger back, will struggle to win a playoff series (or make the playoffs altogether) unless it gets outside help. This is largely because Pierce, in the absence of Rondo, continues to prove himself the team’s most important player.

First, the signs of hope: Without Garnett, Rondo and Sullinger the Celtics led the defending NBA champions by as many as 17 points on Monday night. It took the Miami Heat all 48 minutes to dispose of the depleted Celtics and extend their winning streak to 23 games.

Jeff Green started and scored 43 points in the Celtics 105-103 loss at TD Garden. He joined Paul Pierce as the only Celtics to score 40 or more points in a regular season game since Antoine Walker did it in 2001 (per Jeremy Gottlieb at SB Nation). In the offseason Green, 26, signed a four-year, $36 million contract that will keep him in green (in more ways than one) through the 2015-2016 season. Technically he is very much a part of Boston’s future.

But this game was not an accurate depiction of how the Celtics will look in that not-so-distant future. The 35-year-old captain was still on the floor for 40 minutes. Pierce led the team in rebounds, assists and trailed only Green in team scoring.

Green was brought over from Oklahoma City as a potential replacement for Pierce. He averaged below 10 points per game and shot less than 30 percent from three in his first 26 games as a Celtic. This season, however, Pierce and Greens’ influences on the team are surprisingly similar. The Celtics points and points allowed per possession are identical when either one is on the court (per 82games.com). The key distinction? Pierce plays seven more minutes per game. Boston has scored 32 more points than its opponents with him on the floor this season. Green has not yet proven that he can be an equally consistent positive influence in Boston.

Since Rondo went down, Pierce is averaging 18 points, almost eight rebounds and six and a half assists per game. Before, Pierce grabbed two less rebounds and dished three less assists per game. On top of all that, his shooting percentage from beyond the arc has increased dramatically. With Rondo he made 35.2 percent of his threes. Without him Pierce has made 41.7 percent of them.

Pierce has used his game to glue together a team ravaged by injuries and unfamiliar with playing together.  Green missed all of last season to undergo heart surgery. Jordan Crawford, Jason Terry and Sullinger are (or were) all key players new to the rotation this season.

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Yesterday Danny Ainge discussed the team’s future on the SportsHub, shooing away suggestions that Boston’s more than competent record without Rondo this season (16-7) might justify moving him. He said that the backcourt of Rondo and Avery Bradley is great and provides a bright future for the team.

There is evidence to the contrary, at least from an offensive perspective. Before Rondo partially tore his right ACL, one of Boston’s most-used lineups was Rondo, Bradley, Pierce, Brandon Bass and Garnett. That group logged 123 minutes on the court together during the season, good for the second most of any Celtics lineup. It allowed 0.98 points per opponent possession and could only muster 0.92 points per possession on offense. Its win percentage was just 36 percent, bad enough for the third worst of the team’s other 20 most used lineups. The Rondo-Bradley backcourt makes up 40 percent of a unit that struggles to score.

What can Boston do to bring in outside help? Right now not much. The team is committed to identically restricting amounts of salaries and cap holds for the next two years. The Celtics are paying around $94.5 million this year and will pay about $97.5 million next year.

Don’t expect to see big changes soon, but they need to come. When Pierce moves on, the Celtics might be staring at the “rebuilding” season they’ve worked so desperately to avoid. And that’s without even considering Garnett.