At the beginning of this season Ray Allen did not know Brandon Bass’ injury history, but the NBA’s three-point king concluded from Bass’ preparation that he must have suffered a serious setback many moons ago.

“You must have had an injury at some point early in your career,” Allen told Bass during those early weeks, explaining that he did so because Bass is “very fanatical about his body, and what he eats, and how he stretches. And that’s because he dealt with injury early — in order for him to play at this level, he had to manage his body better.”

Allen didn’t have any major injuries early in his NBA career — he did not miss a single game in any of his first five seasons — but has dealt with several stints on the NBA’s version of the disabled list since, including when he underwent double ankle surgery in 2007, just before being acquired by the Boston Celtics.

Now Allen has returned to the Celtics’ lineup with bone spurs in his ankle, playing through pain to give the Celtics’ bench a boost. In Game 5 he scored 15 points, hit exactly half of his field goals and three-pointers, and did some very Ray Allen things, such as drilling a late triple to tie the game at 83-all with fewer than three minutes remaining.

“The fact that I’ve been through everything, it prepared me for this,” he said before Game 4. “I always say that most athletes — as much as I don’t like saying it — most athletes, it’s the adversity that we go through. If you suffer an injury at an early stage in your career, it almost helps you prepare better in your career. You become a better prepared athlete all around. ”

Allen went from “walking sideways” one day before Game 4 (his words) to feeling “surprisingly great” the next day, even after the rigors of an NBA postseason game. He has been religious in receiving treatment on his ailing ankles, kind of like you might expect from one of the most regimented athletes on earth. The injury has largely taken Allen away from his normal everyday routine, but it’s that same routine that’s helping to save him now, that’s helped his ankles to recover even though he’s a 36-year old shooting guard with more than 42,000 NBA minutes under his belt.

As Allen explained, “That’s why the weight room is so important for us. You may not be getting stronger physically, but it’s important that we continue to keep our bodies taut and aware.”

Without Allen, the bench was almost entirely devoid of scorers and/or play-makers. At this stage of his career Allen is no longer considered an elite play-maker, but his scoring and shooting helped Boston’s bench outscore Atlanta’s 25-9 in Game 5. He provides an extra dimension for the Celtics which they didn’t have before.

Allen’s return wasn’t promised until he started feeling better earlier this week, and he looks at other injuries around the league as evidence that one moment can cut a season short.

Before Game 4, many of the Celtics were watching Heat-Knicks when Baron Davis tore almost every ligament and tendon in his knee.

As Allen explained, “We just saw Baron Davis go down, and that was excruciating to watch. When Noah went down the other day, I turned my head, but I looked. It’s like you don’t want to see it, but you have to look to see it.”

For a long time, Allen feared he too would miss the entire 2012 Playoffs. But thanks to an ankle that finally responded to treatment and a work ethic that has kept him in top shape even during his injury absence, No. 20 is back and helping the Celtics on their quest to reach the second round, and maybe, if everything unfolds the way they hope, even further.