Henderson was suspended from the program in July shortly before Oxford, Miss., police confirmed that he had been found with what appeared to be small amounts of marijuana and cocaine. He was cited only for not having proof of insurance.
He failed a drug test but has complied with all school mandates this summer and fall.
Ole Miss announced the latest suspension Tuesday. Henderson will also not play in Saturday's exhibition game against South Carolina-Aiken. He will miss the opener Nov. 8 against Troy and -- in a unique punishment -- will also miss the first two SEC games, against Auburn (Jan. 9) and Mississippi State (Jan. 11).
Henderson drew negative attention for his animated behavior on the court last season and was ultimately reprimanded by the NCAA in June for making an "inappropriate gesture" after Ole Miss lost to La Salle in the NCAA tournament.
"I want to thank Coach [Andy] Kennedy, [athletic director] Ross Bjork and the university for giving me an opportunity to rejoin the team. This has been a difficult time for me, and I appreciate this chance," Henderson said in a statement released by the school. "My teammates and I are looking forward to defending our SEC championship.''
Henderson was the leading scorer in the SEC last season (20.1 points per game) and led Ole Miss to the SEC tournament title and a win in the NCAA tournament over Wisconsin.
"I support this decision, and I am thankful to our leadership for allowing Marshall the opportunity to earn the right to rejoin our team,'' Kennedy said in a statement. "Marshall has been compliant with the process put in place for him since his suspension in early July, and we look forward to him being back on our team."
Henderson has been practicing with the team and has become a senior leader, Kennedy said earlier this month.
The Associated Press contributed to this report.