The Ants, who finished with the worst record in the D-League last season, have the first pick in the 2012 Draft at 7 p.m. Friday.
Neither Ants President Jeff Potter nor coach Duane Ticknor would comment on the top pick.
“We haven't even seen the complete list (of draft-eligible players),” Potter said. “We should have the list Thursday morning and then we'll research all the different players available.”
Johnson, a 6-foot-10, 220-pound forward, averaged 20.5 points and 8.6 rebounds in his senior season at Purdue, earning All-American honors. He averaged 3.2 points and 1.6 rebounds in limited action while playing in 36 games with the Celtics last season.
Meanwhile, the Mad Ants traded a third-round pick to the Santa Cruz Warriors for 6-10 forward Tommy Smith. Smith, who played at Arizona State, averaged 7.8 points and 4.9 rebounds for the Dakota Wizards last season.
The Ants have already signed veteran guards Walker Russell Jr. and Ron Howard. Other players expected back in camp from last year's team include Jarrid Famous, Cameron Jones, Sadiel Rojas, Thomas Baudinet and Sean Sonderleiter.
Ticknor said the Indiana Pacers also plan to utilize their affiliation with the Mad Ants to gain additional work for their youngest players. Pacers rookies Miles Plumlee, Ben Hansbrough and Orlando Johnson are expected to play at least 10 or 12 games with the Mad Ants this season, Ticknor said.