When Oklahoma State big man Michael Cobbins went down, it dealt a blow to an already thin Oklahoma State frontcourt. Without the big man, the Cowboys are forced to rely on Sophomore Kamari Murphy to do much of the dirty work down low, as he's the only Cowboy taller than 6'7".
Offensively, Murphy could very well be up to the task: he is shooting 64% on the year and has a pretty good 12% offensive rebounding rate. His offensive numbers are even better than Cobbins', but with Murphy playing under 20 minutes per game, it remains to be seen whether he'll be able to adjust to playing many more minutes.
The bigger problem is defensively. While Murphy's block rate is comparable to Cobbins's (6.3% to 7.5%), the Cowboys were allowing teams to shoot under 50% at the rim. Oklahoma State's defense allowed over a point per possession for the 5th time this year in Cobbins's first game out with an injury.
The impact of Cobbins and Murphy down low has been immense. Without Cobbins, they'll have to rely on Freshman Leyton Hammonds for depth. Hammonds doesn't really look like a rim protector and it will likely cause the Cowboys' block percentage to fall around 5%. That is huge for a number of reasons. First, it will allow their opponents to shoot close to 5% higher at the rim, which will in turn raise their eFG by as much as 5%. The other impact is offenses won't fear attacking the paint against OSU, and it will result in more attempts at the rim (and Oklahoma State is already allowing a lot of attempts at the rim). It will also put more pressure on the guards to keep ballhandlers from getting into the paint and, barring superstar calls, will increase their fouls as well.
Michael Cobbins wasn't playing a lot, and he wasn't posting superstar offensive numbers. But his defensive work at the rim and the resulting lack of depth make his loss a huge one for Oklahoma State's Big 12 and NCAA tournament hopes.