By Brian Robb, CBS Boston
BOSTON -- The Toronto Raptors are one of the best offensive teams in the NBA this season, thanks to the stellar play of All-Stars DeMar DeRozan and Kyle Lowry. They play efficient, they play fast and both guards have the size to give Boston's backcourt problems even when the Celtics are at full strength.
The Celtics did an admirable job keeping both in check during the first 24 minutes of Tuesday night's matchup at the Air Canada Centre, but both got going in the second half. That's not particularly surprising when you consider Avery Bradley was out of the lineup for Boston.
While DeRozan will get most of the headlines for his 41-point performance in the Raptors 114-106 victory, a more concerning Celtic problem resurfaced again in the defeat: Boston's inability to keep teams off the offensive glass.
The issue has been Boston's Achilles heel all year long, but they had managed to overcome it in recent weeks with superior offense and effective gang rebounding. However, in a playoff-type atmosphere up north and an imposing big man in Jonas Valanciunas to contend with, the Celtics didn't have an answer.
Boston allowed Valanciunas to snag 11 of Toronto's 17 offensive rebounds on the night (23 boards in total). That was a career-night for him on the glass, and demonstrated once again how helpless Boston's frontline of Al Horford, Amir Johnson and Kelly Olynyk can be against the wrong opponent.
When all was said and done, the Raptors collectively grabbed 38 percent of all available offensive rebounds, meaning the Celtics had to defend multiple consecutive possessions more than a third of the time they forced a miss. Against a top notch offense like Toronto, that's a recipe for disaster. The problem was magnified most during the Raptors' 68-point second half when the hosts grabbed 11 offensive rebounds on just 23 missed field goal attempts.
"We've got to shore up the rebounding," Stevens said to reporters after the game. "That's a huge part of our defensive issues. I thought they were clearly the more physical team for those 12 minutes."
The problem was even worse for the Celtics when Horford was on the floor, as noted by prominent gambler Haralabos Voulgaris:
With rebounding rates at career-lows for Horford and Johnson, Tuesday's defeat should serve as a reminder that the Celtics could use a true center up front that can hold his own on the glass. Toronto is a likely second round opponent for the Celtics in the postseason, and it doesn't appear they have the personnel up front to get by them in a seven-game series right now. Boston has now dropped five of their last six to the Raptors.
"My biggest thing is we have to get a lot better," Stevens said. "I said that before we met today for this game and I probably saw more encouraging signs of progress than I did negative, but at the end of the day they had their way in the last six minutes of each of the last two quarters."
While Danny Ainge may have to wait for more teams to fall out of the playoff race to find a big that is a good fit for this roster, it's more clear than ever that rebounding is an area that must be addressed by the trade deadline. If the Celtics are serious about making a deep playoff run, they need some help down low.
Brian Robb covers the Celtics for CBS Boston and contributes to NBA.com, among other media outlets. You can follow him on Twitter @CelticsHub.
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