Boston Celtics guard Avery Bradley, sidelined by an Achilles strain, sat out for the 15th time in his team's past 16 games during Wednesday's 108-92 loss to the Sacramento Kings. It's unlikely that Bradley could have prevented this rare dud -- the Celtics hadn't endured a loss this lopsided since November -- but watching the Kings hang 31 points in the fourth quarter, it was one of a few recent reminders that the Celtics are playing without their best defender.

What has been remarkable as the Celtics have climbed to the No. 2 spot in the Eastern Conference is just how well they've typically played despite their injuries.

Boston's four primary starters -- including Avery Bradley, right, and Isaiah Thomas -- have combined to miss 40 games this season. Winslow Townson/USA TODAY Sports

Boston's four primary starters -- Bradley, Isaiah Thomas, Jae Crowder and Al Horford -- have combined to miss 40 games this season. In fact, the Celtics have had that core four together in the starting lineup just 22 times. That Boston is 16-6 when all four have started together offers a glimpse of this team's potential when healthy.

But even though coach Brad Stevens has had to routinely patch his starting lineup, the Celtics still find themselves at 33-19 overall and have a two-game lead over the Raptors and Wizards in the East. Wednesday's loss snapped a season-best seven-game winning streak for a Boston team that won 14 of its previous 18 overall.

According to the latest data from injury-tracking website ManGamesLost.com, the Celtics rank in the back half of the league (18th overall) in terms of total games missed because of injury through Feb. 5. But because starters make up a good portion of those absences, Boston rockets toward the top of the site's rankings in "lost value over replacement player" and "injury impact to team VORP." In the latter category, the Celtics trail only the snakebitten Clippers.

Stevens said Tuesday that it's unlikely Bradley will join the team on this four-game road trip, and he could be out through the All-Star break. Take away a premature one-game return in mid-January, and Bradley could miss roughly 50 days of game action -- or about 30 percent of the regular season -- if he ultimately returns after the break.

Stevens does not allow his team to lean on excuses for not being competitive. This is most notable when it comes to back-to-backs. The Celtics, with a veteran roster under Doc Rivers at the end of the Big Three era, often struggled on the tail end of back-to-backs. Stevens demands his teams embrace the quick turnarounds, particularly with a more youthful roster. Boston is 8-3 on the second night of back-to-backs this season, winning eight of their past nine overall.

Thursday's visit to the Portland Trail Blazers provides another opportunity to embrace the back-to-back.

Stevens has taken a similar approach with injuries. The Celtics have so routinely been without a key player this season that it's simply expected they'll plug someone into the hole and experience no great drop-off.

Stevens has used 11 starting lineups this season. Early in the year, he had the luxury of inserting Marcus Smart at either guard spot or at small forward to cover injuries to Thomas, Bradley and Crowder. More recently, he has leaned on rookie Jaylen Brown in Bradley's void, with a desire to keep Smart in his spark-plug role off the bench.

Instead of harping on who hasn't been on the court, Stevens keeps his focus on the valuable playing time the team's youngest players are getting because of injuries.

"Terry [Rozier] and Jaylen -- this stretch of games has been huge for them because it’s given them more opportunity with one of our best players out," Stevens said. "And we never know exactly how we’re going to end the game, from a lineup standpoint, because both of those guys have shown continued promise."

Starting has given Brown a little more freedom to spread his wings. Stevens can still be quick with a hook when the rookie struggles defensively, but Brown, the No. 3 pick in June's draft, is getting valuable floor time during Bradley's absence. His confidence is growing, and Stevens has obvious faith in Brown's ability to fill a key rotation role on a playoff-bound team, something that's not typical of a rookie, let alone one who only recently turned 20.

"It’s cool [starting]; whatever is asked of me is a blessing," Brown said. "We're a really, really good team, we’re second in the East right now. To be starting [recently] has been fantastic. ... I feel like I know how to get involved, I know my teammates, my teammates know how to get me the ball. Before I struggled with picking my spots, and now I know where my spots are in the post, corner 3s, back cuts, getting to the basket. It’s a little bit more fluid."

Regardless of Boston's activity at this month's trade deadline, Boston will be adding at least one impact player by getting a healthy Bradley back on the court. It would certainly help the Celtics to get at least a few weeks where all their key rotation guys are upright and able to build some chemistry before the postseason arrives.

But even if they don't, Stevens won't fret. Injuries are part of the job, and the Celtics haven't let them detour them from making the strides expected this season.