Costello has been a key for MSU all season and he showed again in Tuesday night's win over Ohio State University just how important he is. MSU led by only five points at halftime as Costello sat out the final 11 minutes with two fouls and only four points. After a stern talk from MSU head coach Tom Izzo, Costello came out in the second half and scored 12 of his 16 points, while grabbing five of his six rebounds as MSU pulled away for a 19-point win. 

MSU is No. 1 in the country in shooting the three, averaging 43.2 percent from behind the 3-point line, but Costello gives MSU the inside-out game it so desperately needs. And with freshman forward Deyonta Davis not having a fully developed post-game yet, and who also never uses his left hand, and junior Gavin Schilling's inconsistency and foul trouble, that leaves Costello to be the answer on the inside. 

MSU is 6-1 in games in which Costello has a double-double. Meanwhile, MSU has proven it can win a game when Valentine is held under 20 points or misses a game all-together, going 16-1 in such games, with the only loss coming at home against Iowa. 

Not only is it the inside presence that makes Costello irreplaceable, it is also his infectious energy. The same energy and goofiness has jolted this team and helped lead it to seven wins in MSU's last eight games, beginning with MSU's win over Maryland, which also broke MSU out of a three-game losing streak. 

Costello entered that game thinking he would be severely limited by an ankle injury, but fought through the pain, and played with such energy and urgency that he scored 15 points, grabbed 12 rebounds and hit the floor several times going after loose balls, all culminating with a bear hug for Izzo as he went to the bench at the end of the game. 

During that game MSU followed Costello's lead. The rest of the players saw the energy Costello was playing with for 32 minutes on a bad ankle and were inspired to follow suit. 

Since then, Costello's only bad game arguably came in MSU's loss to Purdue. Costello finished that game with 11 points and five rebounds. Costello said later he was dominated by Purdue senior big man A.J. Hammons, who blasted Costello for 19 points, a season-high 13 rebounds and a season-high eight blocks. 

If Costello can be more consistent and locked-in defensively down the stretch, not only will he break MSU's all-time block record, which he is only five blocks away from breaking, but he will be crucial as MSU battles bigger and more athletic front lines in the NCAA Tournament.

Add the fact that Costello has developed a very solid mid-range jump shot and even shown an ability to shoot the three, which will make him all the more dangerous come March, as teams might be hesitant to double a guard on a ball-screen for fear of Costello either catching the ball and going in for a layup, or knocking down a midrange jumper shot off a pick-and-pop. 

Not to mention his 54.5 percent shooting from the floor or his 74.3 percent free throw shooting, which will allow him to stay on the court during the closing minutes of close games without Izzo having to worry about Costello being forced to shoot clutch free throws.

So while Valentine might be MSU's best player, it is fellow senior and good friend Costello who could hold the key for MSU to make a deep run in March if he is able to stay out of foul trouble and bring his infectious energy game in and game out.