The Rebels are 2-0 following a 67-51 win over Northwestern State on Friday.
Through two games, Ole Miss guard Diara Moore, a junior college transfer, is tied for first in scoring in the SEC with 19 points a game.
Lamar is 2-1, winning back-to-back games after losing its season opener to then-No. 1 Baylor.
Lamar beat the Rebels last year 67-58 in Beaumont, Texas.