No defense for regression

When the Boston Celtics reconvened in Phoenix following the All-Star break, coach Brad Stevens was under no delusion that his team was poised for any sort of playoff charge, but after spending much of the break assessing his team's first-half play, he set a reasonable goal of simply making an extra stop or two per game defensively.

Over the first 54 games of the 2013-14 season, the Celtics had ranked 14th in the league in defensive efficiency, giving up 103.2 points per 100 possessions. It was that defense that masked an anemic offense and helped the team stick around in games.

While Boston continues to hang around in games, the regression on the defensive end since the All-Star break has to be gnawing at Stevens. The Celtics have posted a defensive rating of 107.6 over their last 18 games, ranking 22nd in the league in that span. Maybe it's no surprise that the team is only 4-14 during that time.

The Celtics' defensive woes continued Friday night in Toronto. Make no mistake, DeMar DeRozan made some absolutely ridiculous shots as part of his 30-point outburst, but Boston also allowed a staggering amount of penetration, which helped the Raptors generate easy points near the basket as nearly half of Toronto's total offensive output came in the paint.

Yes, the absence of a true rim protector remains glaring for these Celtics. But Boston's defensive woes extend beyond the lack of a 7-footer to be disruptive around the basket. Just take the deciding bucket of Friday's game.

The Raptors ran a simple high pick-and-roll with Kyle Lowry coming off an Amir Johnson screen that snagged Avery Bradley about eight feet beyond the 3-point arc. Trouble came when Jared Sullinger got caught leaning a bit and Lowry cut back a bit and raced at the basket. Sullinger managed to contest and force a miss, but Bradley failed to put a body on Johnson, who followed the play and completed the putback with 7.1 seconds to play.

Bradley and Sullinger are two of Boston's better individual defenders, but their lapses hammer home the slippage that has plagued the Celtics. Instead of generating the one or two extra stops that Stevens desired in late February, Boston is giving up an extra bucket or two and hasn't been able to win close games lately.

On Friday night, the Celtics shot 52.6 percent overall and yet still found themselves down as much as 14. Boston needed a feverish fourth-quarter outburst from Jerryd Bayless (14 of his team-high 20 points in the final frame) to help get them back in the game, only to be unable to hang on to a four-point lead with little more than two minutes to play.

Sure, we wonder how much different things would be if the Celtics had any sort of pure size at the center spot, the sort that would allow Sullinger to play at his more natural power forward position. But you can't pin all of Boston's woes on that. The Celtics have had their preferred Bradley-Rajon Rondo combo in place for recent games and yet the team continues to allow an unnerving amount of penetration.

Boston's current starting unit -- Rondo, Bradley, Jeff Green, Brandon Bass, and Kris Humphries -- have a defensive rating of 113.9 in 55 minutes of court time over eight appearances together since the All-Star break. Boston's most used lineup in that span swaps Bayless into Bradley's spot (given the time he missed because of injury) and that unit hasn't been much better with a defensive rating of 109.1 in 110 minutes of court time.

The result is a Boston team that has routinely been staring at double-digit deficits entering the fourth quarter. The Celtics' bench has helped the team rally back at times, but Boston's inability to generate consistent late-game stops has resulted in a Groundhog Day-like pattern to losses.

Listen, it's hard to get overly worked up about defensive woes when the focus is on the future and every loss leaves the Celtics a little closer to obtaining a better draft pick. But you know it has to be eating at Stevens a bit to see regression instead of progress at this point.

The Celtics were establishing an identity earlier in the year with their defensive play, making that the backbone of their team. But that has faded recently and Boston's defense has failed to make the strides Stevens was looking for over the final 30 games.