Before P.J. Brown became the modern standard by which all Celtics veteran free agent acquisitions are judged, there was some question as to whether the veteran power forward still had game.

Brown was nominally retired and hadn’t played all season when he was coaxed into coming back for one more go-round, and it showed. In 18 regular-season games he averaged a mere 2.2 points and 3.8 rebounds.

Once the playoffs began, however, Brown proved to be an invaluable part of the Celtics championship run with tough defense, timely rebounding and an uncanny ability to make clutch shots. All that made him a minor folk hero, but he had already supplied the Celtics with something of value. 

While he was getting himself back into basketball shape, Brown took young Leon Powe under his wing. After 14 seasons in the NBA, Brown didn’t need to add mentor to his resume, but in Powe he found a hard-working kindred spirit, and the two became inseparable, with Powe soaking up lessons from the master.

New Celtics acquisition Michael Finley is a lot like Brown in some ways. After 14 NBA seasons, no one really knows how much he has left. But what we do know is that he, like Brown, is regarded as the consummate professional and locker room leader.

Marquis Daniels, who broke in with Dallas when Finley was still good for 18-20 points a night, said Wednesday night that Finley is a “great locker room guy. Great guy, period.”

The Celtics are not a young team in search of a veteran sage, but it certainly doesn’t hurt his cause that Finley is held in such high esteem.

The question for Finley, who turns 37 on Saturday, is how much does he have left?

One season removed from starting 77 games for the San Antonio Spurs, Finley has played in just 25 games. He fell out of the rotation in late November and had appeared in just 10 games since the demotion.

On Feb. 26 he went 0-for-5 and missed all four shots in 20 minutes in a game against Oklahoma City. That was his longest outing since Nov. 29.

Finley asked for his release from the Spurs and they granted his request. Other contending teams were said to be interested in him. Some had more resources available than the veteran’s minimum that the Celtics had to offer, which shows how much he wanted to come to Boston.  

Finley has undergone several transitions throughout his career, which helps explain his longevity.

With the Mavericks he was a two-time All-Star and a high-scoring iron man who led the league in minutes played on three occasions. He once averaged a fairly-incredible 46.6 minutes during the 2001-02 playoffs covering eight games.

Toward the end of his run in Dallas, Finley became more of a perimeter threat and he carried that transition to its logical conclusion during his four and a half seasons with San Antonio where he served as a valuable role player.

The high point for his time with the Spurs came during the 2007 playoffs when he averaged better than 11 points a game and shot 42 percent from 3-point range to help them capture the championship.

With the Celtics, Finley will have to fight for minutes in the backup wing rotation with Marquis Daniels, Tony Allen and Brian Scalabrine. He immediately becomes the best shooter in that group, even accounting for his lackluster numbers this season.

His presence also allows Daniels to continue to play multiple positions and not just serve as Paul Pierce’s backup. If anyone’s minutes are going to get squeezed because of Finley it will probably be Tony Allen’s, who has quietly put together a useful season.

Appearing on The Big Show Wednesday afternoon, Danny Ainge noted that Finley wasn’t going to be the difference between winning and losing a championship, which is true.

But considering his reputation, and the very available roster spot, it’s a no-risk proposition for the Celtics with some potential for a decent reward. That sounds a lot like P.J. Brown two years ago. Now we’ll just have to see if Finley has some game left too.