CLEMSON — Dabo Swinney has proven the ability to close before.


On signing day 2011, Clemson landed a pair of five-star football recruits in Tony Steward and Stephone Anthony. In 2009, Tajh Boyd chose Clemson over Ohio State and Oregon late in the signing period.


Swinney must add to his reputation as a closer if Clemson is to lift its 2013 class from good to great status.


Clemson enters National Signing Day today with a class ranked 21st in the nation by Rivals.com, 18th by 247Sports.com and 18th by Scout.com. Only ESPN ranks Clemson’s group of four early enrollees and 14 commitments as a top-15 class (15th).


But two faxed signatures could push the class into top 10 territory. The Tigers are in the mix for two elite prospects in five-star defensive tackle Montravius Adams (Vienna, Ga.) and five-star cornerback Mackensie Alexander (Immokalee, Fla).


The drama will be televised.


Adams will announce his decision – likely between Clemson, Auburn and Georgia – at 9 a.m. on ESPNU, and Alexander will follow with his choice at 11 a.m. on ESPNU. Alexander’s finalists are Auburn, Clemson, Mississippi State and Texas A&M.


Clemson’s also battling Georgia for Tyrone Crowder, one of the nation’s better guards. He will announce his decision at 4 p.m. on ESPNU.


Clemson was the first school to offer Adams, which could work in its favor. Four Clemson coaches visited Adams at his home on Friday. Over the weekend Adams visited Auburn.


The 6-foot-2, 280-poound Adams has the quickness and strength to provide an immediate impact along the defensive front.


The Tigers are thinner in the defensive backfield where Alexander would be a welcomed addition as ESPN’s No. 4 overall player. The 5-11, 175-pound Alexander has kept a low profile during the recruiting process.


Even without Adams or Alexander, Clemson still has a solid class that contains nine four-star talents.


Four-star defensive ends Shaq Lawson and Ebenezer Ogundeko are already enrolled. Four-star running back Tyshon Dye could also make an early impact as Clemson lacks depth in its backfield. Outside linebacker Dorian O’Daniel, middle linebacker Ben Boulware, wide receiver Mike Williams, Hawaiian defensive tackle Scott Pagano and South Florida athlete Jayron Kearse are among the other intriguing talents in the class.