For the first time in more than a year, the Toronto Raptors have lost three games in a row. The last time Dwane Casey's bunch had a losing streak this long was 13 months ago, back when Rudy Gay was still running isolations on the wing and Kyle Lowry was a player most considered to be a borderline All-Star.

A lot has changed since then. Lowry has morphed into one of the best players in the league and an MVP candidate. He's also helped transform the Raptors' offense into a machine and the team into a Eastern Conference contender. The Raptors are 24-10, just one-and-a-half games behind the first place Atlanta Hawks (!). This despite playing the last 18 games without DeMar Derozan, who's been out with a groin injury.

But for all that success, the good might not be enough to cover up the bad. Toronto's defense, one of its calling cards last year, has slipped badly and is the source of the team's current skid. The Raptors are allowing opponents to score 105 points per 100 possessions this season, the ninth-worst mark in the league. Teams are shooting 46 percent from the field, the seventh-highest number in the NBA.

Pick a random defensive statistic and you'll usually find the Raptors listed somewhere on the bottom half of the page. That's the most troublesome part: it's not like one can point to just one area where Toronto has struggled and say that's what needs to be fixed. The only thing the Raptors are especially awful at is pulling down defensive rebounds. They've allowed opponents to score more almost 15 second-chance points per game, the third-worst number in the league.

When it comes to playing defense, Toronto is below average at everything and good at nothing.

This issue has become even more magnified during the the Raptors' current three-game losing streak and the team's last six games, five of which came against good Western Conference teams on the road. In this six-game stretch, the Raptors are surrendering 114 points per 100 possessions, per NBA.com. For a comparison, the Timberwolves, who are giving up 110 points per 100 possessions on the season, are currently last in the NBA in defensive rating.

The Raptors' inability to contain point guards has been root of the problem recently. In their 125-108 loss Sunday night against the Suns, Toronto was carved up by Phoenix's three-headed monster of Eric Bledsoe, Goran Dragic and Isaiah Thomas. The three players combined to score 56 points by hitting 21 of 33 shots. Thirteen of those makes came at the rim. Below you can see some of the highlights.

Among the highlights:

You'll see Dragic receive a give-and-go pass from the top of the key and have no one within three feet of him.

You'll see the diminutive Thomas drive baseline and somehow take an uncontested layup.

You'll see Bledsoe easily beat the Raptors' pick-and-roll defense.

These miscues didn't come out of nowhere. The Raptors were torched by Stephen Curry two nights prior for 32 points. Damian Lillard went for 26 on Toronto in an overtime win last week. Ty Lawson dropped 28 on the Raptors the game before that, though Toronto did pull out the victory. The Raptors kicked off this current road trip by allowing Derrick Rose to score 29 points in a 129-120 Bulls win.

In a league where you have to face a top point guard almost every night, this is not a good problem to have. The Raptors have been one of the pleasant surprises in the league and the impending return of Derozan will only help things. The Raptors' defense wasn't great with Derozan, but it was certainly better than it's been since he went down. Before Derozan got hurt the Raptors had a defensive rating of 106. In the 18 games without him, the've allowed opponents to score 108.6 points per 100 possessions, the third worst number in the league.

That said, neither number is good enough, so Derozan's return to the lineup might not be as a big a boost as many think. As outlined by our own Mike Prada in this post, when Derozan was playing, the Raptors were still letting opponents take too many shots from the spots (the paint, corner 3s) that they should be aiming to take away.

The Raptors will probably remain around the top end of the East's standings all season because the East stinks, but if they want to go far in the playoffs, they need to sort out their defensive issues. You can't be in the bottom third in the league on that end of the floor and expect to win games in May and June.