Thomas, 19, was arrested and jailed by Ames, Iowa, police early Saturday before he was bailed out by his brother, according to a source close to the program.
Thomas, a Wisconsin native who was ranked No. 51 in the 2013 class per RecruitingNation.com, averaged 5.5 points for the Cyclones last season.
Coach Fred Hoiberg met with his team Saturday morning to discuss the incident prior to participating in a charitable walk to raise money for heart disease research in Des Moines, the source said.
Thomas did not attend, but he's expected to be suspended as a result of the incident, the source said.
Abdel Nader, a transfer from Northern Illinois, was arrested for driving while intoxicated in April. He pleaded not guilty to the charge in May and is set to appear in court later this month.
Nader, who sat out during the 2013-14 season, was suspended indefinitely after the arrest.
Hoiberg and his staff are set to leave for Greece on Monday to check on Georgios Tsalmpouris, a 7-foot-1 big man who will join the program this fall after spending time with the Greek national team.