CSNPhilly.com is providing position previews leading up to the NBA draft on June 27, ranking the top five prospects at each position. We've already covered point guards, shooting guards and small forwards. We continue today with the deepest position in this year's draft, the big men -- encompassing both the power forward and center positions.

1. Nerlens Noel, C, 7-0, 205, Kentucky
Noel is far from a sure thing, and I wasn't impressed with his abbreviated body of work at Kentucky. His offensive game needs a significant amount of polish, but he is an NBA-caliber shot blocker and defender, evidenced by his staggering 4.4 blocks per game last season. To be fair, he improved offensively during the course of his freshman season. Noel averaged 10.5 points, 9.5 rebounds and shot 59 percent from the field in 24 games. However, he shot less than 53 percent from the foul line, something he must improve to avoid being a liability in end-of-game situations. Noel also needs to bulk up substantially after losing a good deal of weight while sidelined with an ACL tear suffered in mid-February. His return date from that injury is unknown, but he certainly won't be ready for the start of the regular season in late October. If he takes the Derrick Rose cautious approach, he could be sidelined until March. Noel's potential outweighs all the question marks, and he's the frontrunner to become the No. 1 overall pick. If Cleveland passes on him, he'll likely land with the Magic at No. 2 and would drop no lower than the Wizards at No. 3.

2. Alex Len, C, 7-1, 225, Maryland
Len is beginning to generate buzz as the potential top-overall pick because of his sought after combination of size and skill. He put up solid numbers playing against high-level competition in the ACC. Len averaged 11.9 points, 7.8 rebounds, 2.1 blocks and shot better than 53 percent. His offensive skills translate nicely to the next level, but the biggest question is whether he will be physical enough for NBA post play. Len will be sidelined for the next 3-5 months with an ankle injury, but that shouldn't have too big of an impact on his draft status. He's looking more and more like a lock to go in the top five, and could possibly go as high as No. 1 to Cleveland.

3. Cody Zeller, PF, 7-0, 230, Indiana
Everyone has strong opinions on Zeller, mostly negative following a "disappointing" sophomore season. I put disappointing in quotes because he averaged 16 points, eight rebounds and shot 56 percent for a national championship contender. But Zeller was tabbed the preseason player of the year after he decided to return to school for his sophomore season, and he didn't live up to those expectations. But the bottom line with Zeller: He's a legit 7-footer who has good ball skills and can score. That combination tends to go over well in NBA circles. Zeller should be selected in the 8-13 range, and is a legitimate candidate to go to the 76ers with the 11th pick.