The main reason Michigan lost a heartbreaker to Indiana on Sunday—yes, even more than their late-game free throw misses—was their inability to keep the Hoosiers off the offensive glass. Indiana rebounded 24 of their 40 missed shots; once second in the country in defensive rebounding, the Wolverines are now eighth in their own conference.

What's odd about this at first glance is that Michigan boasts a trio of centers who are all proficient rebounders. Jordan Morgan (#9) and Mitch McGary (#5) both rank among the top Big Ten players in defensive rebounding percentage, and Jon Horford would rank just ahead of Morgan if he played enough minutes to qualify.

After looking at the film, it's apparent that Michigan's bigs lack the support they need to defend the boards; the team's overall inexperience and poor perimeter defense are most apparent in this area. One play in particular from the Indiana game bears this out:

Let's look at this frame-by-frame, starting with the defensive lapse that begins the sequence—Tim Hardaway Jr. falling asleep in the corner and allowing Victor Oladipo to beat him on a backdoor cut:

Zeller has no problem getting the ball to Oladipo in great position for a shot. With Zeller and Jeremy Hollowell (#33, on the other side of the FT line from Zeller) at the top of the key—drawing Jordan Morgan and Glenn Robinson III way from the basket—Hardaway must fend for himself:

Here's where Michigan's rebounding issues begin in earnest. This is the point where Oladipo releases his shot. Note that Zeller, Morgan's man, has stayed on the perimeter, while Hollowell is crashing the paint behind Robinson. Hardaway is accounting for Oladipo and Robinson should be responsible for Hollowell; both are in decent position right here, while Nik Stauskas has been beaten to a good rebounding spot by Will Sheehy:

At the moment before Oladipo secures his own rebound, however, it's clear that Michigan's perimeter players haven't done their job. Hardaway first goes for the block and then reaches for the ball instead of putting a body on Oladipo, who will easily step by him and get the board. Robinson has watched the ball the entire time and allowed Hollowell a free pass to the basket. Stauskas is lucky not to give up a putback after letting Sheehy get right under the basket. Morgan is in solid position but the ball doesn't bounce his way. This is not good:

Oladipo kicks the ball out to Jordan Hulls, who gets a wide-open look from three after Trey Burke drifted away from the play. At the moment Hulls releases his shot, most of Michigan's players have at least partially recovered—Burke is attempting to close out, Morgan is on Zeller, and Hardaway and Stauskas have found their men. Robinson, however, is still watching the ball, unaware that Hollowell is on the complete opposite side of the lane:

As the shot comes off the rim, you can see three Wolverines—including Robinson—trying to box out two Hoosiers on the left side of the lane, while Morgan is left with the unenviable task of being one guy having to guard two guys:

This, predictably, does not go well. Zeller taps the rebound to Hollowell, who's able to gather the ball and go up for a layup despite Morgan's best efforts to be two Jordan Morgans.

To sum up, on this play we've got:

• Hardaway falling asleep on a backdoor cut
• Stauskas getting beat along the baseline
• Hardaway not boxing out Oladipo
• Robinson not boxing out Hollowell
• Robinson not boxing out Hollowell again, nor even being in the same general area

Watch Robinson throughout the play, here in handy gif form:

He never leaves an area covering about 15 square feet until it's far too late. You know how coaches say the key to a freshman succeeding is having the game slow down for him? On defense, at least, the game is going about 200 mph for Robinson, who's trying to defend with his eyes instead of his feet—while he's watching the ball, he's losing his man.

One play doesn't make a trend, of course, but there were several other instances of Michigan's non-centers being the culprit for an offensive rebound.

[For more rebounding pain and suffering, hit THE JUMP.]

This is another example of Robinson failing to stay with his man. Off a baseline out of bounds, Indiana gets the ball to Yogi Ferrell, and the pre-inbounds screen action leaves Robinson on him after a switch. Ferrell drives the baseline and has to chuck the ball back out to to the top while falling out of bounds. While Indiana resets, Robinson fails to pick Ferrell back up, eventually getting beat baseline off the dribble. Jon Horford has to rotate over and help, allowing the Hoosiers to grab two more offensive rebounds before drawing a foul:

While bad rotations often lead to offensive rebounds, plain getting beat off the dribble tends to have the same result, as well. In this clip, Robinson is beat clean to the basket on a Christian Watford drive. Jordan Morgan has to slide over and attempt to take a charge. Watford misses, but Morgan is on the floor as Watford tries a putback, and in no position to box out Zeller when he tips in Watford's second miss:

Finally, there's simple bad decision-making. On this Zeller post touch, Trey Burke reaches for an improbable steal attempt instead of putting a body on Sheehy, who slips right by him for a critical second-chance basket:

While the Indiana game provided the most recent—and most painful—example, Michigan has struggled to rebound in most of their games against top conference competition (Wisconsin is an outlier in more ways than one). The concern, this deep in the season, is that it's too late to fix the issue before next season. If the light hasn't gone on defensively for Michigan's freshmen—especially Robinson and Stauskas—it's probably not going to happen in the next couple weeks. Hardaway is the veteran in the rotation, but three years into his career he still has regular defensive lapses (he also failed to close out on two critical second-half Hoosier threes). Burke's stepped up his on-ball defense significantly, but as a point guard he isn't going to have a big impact on the glass.

Michigan has enough talent and ability to make a deep run both this weekend and in the NCAA tournament. To go far, however, they're going to have to overcome their rebounding problems, and at this point offsetting them with an offensive explosion seems more likely than eliminating them entirely.