North Carolina's national title aspirations took a major hit on Sunday after the Tar Heels learned that star point guard Kendall Marshall has a fractured right wrist injury that required surgery.

Marshall, the best pure-passer point guard in the college ranks, underwent surgery on Monday, but it's unknown whether he'll be able to suit up again for North Carolina this year. Marshall is a natural lefty so the injury occurred on his off-hand, but it's still difficult to imagine him being able to effectively run the fast break with only one good hand.

It's a huge blow for the Tar Heels for two reasons: Marshall is an incredibly effective point guard that makes the whole machine run; and there is no backup point guard that can come even close to filling his void if he's out for the rest of the tournament.

Depth has been an issue for the Tar Heels all season, but they are especially thin at the guard position. The Tar Heels lost Leslie McDonald to an ACL injury before the season started and lost starting shooting guard Dexter Strickland to a season-ending ACL injury in January. If Marshall misses considerable time, either senior guard Justin Watts or freshman guard Stillman White will be counted upon to carry the considerable load.

Both players have largely been used in mop-up situations and have never played the type of minutes that might be needed from them in the Sweet 16 against Ohio. The Tar Heels should have too strong of an inside presence with Tyler Zeller and John Henson to be upended by Ohio, but a looming Elite Eight game against Kansas could be quite dicey without Marshall.

It's a difficult pill for the Tar Heels to swallow given the expectations they had for this season. North Carolina coach Roy Williams caught a major break when Zeller, Henson, and Harrison Barnes all decided to return this season, but it is very likely that he will lose all three to the NBA Draft.

Power of Ohio

For the first time in NCAA Tournament history, four teams from the same state have made their way to the Sweet 16. The state of Ohio was an impressive 8-0 in the first two rounds of the NCAA Tournament and saw Cincinnati, Ohio, Ohio State, and Xavier all advance to the Sweet 16.

Ohio State's run to the Sweet 16 was expected by many, but the other three are a bit of a surprise. Ohio knocked off rival Michigan in an impressive upset in the Round of 64 and then took down South Florida to advance to its first Sweet 16 in program history.

Cincinnati and Xavier might be an even bigger surprise to advance to the Sweet 16 given their Crosstown Shootout brawl in December. The two teams engaged in one of the ugliest brawls in college basketball history and looked destined to see their seasons spiral out of control, especially Xavier.

Xavier came into the season with very high expectations, but struggled mightily after the brawl. The Musketeers lost five of their six games after the brawl and looked like they might not make the NCAA Tournament at all before coach Chris Mack got his guys back on track at the end of the season.

Cincinnati had to deal with significant suspensions for some of its top players, including Yancy Gates, but regrouped after the brawl and really bought into what coach Mick Cronin was preaching. They outlasted Florida State in a brutal Round of 32 game and now have an opportunity to knock off rival Ohio State in a highly-anticipated Sweet 16 matchup.

Top 3 Sweet 16 Games

All of the Sweet 16 games could be entertaining in their own right, but a few really stand out.

1) No. 4 Louisville vs. No. 1 Michigan State

Two of the nation's top coaches -- UL's Rick Pitino and Michigan State's Tom Izzo -- square off in what figures to be a fantastic Sweet 16 game. Michigan State flew under the radar for the majority of the season, but with the help of star forward Draymond Green, seem to be peaking at just the right time. Louisville is another team that seems to be peaking -- they've won their last six games. Point guard Peyton Siva has really come on of late and could be a handful for the Spartans to deal with.

2) No. 4 Indiana vs. No. 1 Kentucky

It's hard to try to keep the consensus No. 1 team motivated, especially if you are going with an us against the world strategy, but Kentucky coach John Calipari has used an early season loss to Indiana to motivate his guys. Calipari has said that his players grew annoyed with ESPN constantly showing highlights of Indiana's win over the Wildcats and used it to cruise through the rest of the season before a SEC Tournament loss to Vanderbilt. Indiana has shown it can knock off Kentucky, but the Wildcats will do everything in their power to get that revenge when it counts the most.

3) No. 6 Cincinnati vs. No. 2 Ohio State

Cincinnati and Ohio State make perfect sense as natural rivals, but the two teams have only played each other in the regular season once in the last 49 years. Cincinnati coach Mick Cronin told Yahoo Sports that the reason they haven't played is due to Ohio State's unwillingness to play, while Ohio State's Thad Matta stated that the Buckeyes simply try to play as many teams out of state to appeal to get more national exposure. You better believe that both these teams are going to bring it in the Sweet 16, especially the Bearcats.

Top 3 Remaining Teams

1) Kentucky

The Wildcats are still the clear favorite to win their region and ultimately a national championship. Kentucky easily dispatched its first two opponents on the way to the Sweet 16 and has every motivational reason in the world to knock off Indiana. From there it would face either Baylor or Xavier -- both teams it should be able to overwhelm.

2) Kansas

Kansas struggled mightily against a Robbie Hummel-led Purdue team on Sunday, but has a nice Final Four path ahead. The Jayhawks have a very winnable game against North Carolina State in the Sweet 16 and then will likely play a North Carolina team missing its key playmaker Kendall Marshall. Kansas certainly has its share of issues, but has one of the remaining one-two punches in the tournament with Tyshawn Taylor and Thomas Robinson.

3) Michigan State

The Spartans have largely been devoid of hype in the lead up to March Madness despite being a No. 1 seed. Michigan State has one of the top five players in the country with Draymond Green and play like a typical Tom Izzo coached team - hardnosed, smart, and heady. Michigan State has a very difficult Sweet 16 game against Louisville, but has a very nice chance to return to the Final Four if they can get by the Cardinals.

TV Schedule for the Sweet 16

March 22:

7:15 p.m. EST: Wisconsin (4) vs. Syracuse (1)

7:47 p.m. EST: Louisville (4) vs. Michigan State (1)

9:45 p.m. EST: Cincinnati (6) vs. Ohio State (2)

10:17 p.m. EST: Florida (7) vs. Marquette (3)

March 23:

7:15 p.m. EST: Xavier (10) vs. Baylor (3)

7:47 p.m. EST: Ohio (13) vs. North Carolina (1)

9:45 p.m. EST: Indiana (4) vs. Kentucky (1)

10:17 p.m. EST: N.C. State (11) vs. Kansas (2)