Smaller classes and mandatory face masks are likely to be part of Purdue University's plans to return students to campus this fall, Mitch Daniels, its president, told CNBC on Monday.

"You can expect smaller numbers in every context," Daniels said on "Power Lunch." "I know we're looking for ways to reduce the size of classes, obviously keeping distance between people. Probably going to see masks as a requirement, at least for a long time here."

Daniels, the former two-term Republican governor of Indiana, where Purdue is located, said the university also would likely forgo the large events "that enliven life" on campus such as "lectures and guest speakers and convocations of that kind."

"All those things and many more, changes to our physical facilities, for instance, will be necessary for us to conclude that we are safe," Daniels said. "We won't move forward unless we believe that, but to get to that point, we have to get going now."

Daniels wrote a letter to the university community last week, in which he stressed many of the proposals to return to in-person classes were "preliminary." They should be viewed "as examples, likely to be replaced by better ideas as we identify and validate them," he wrote.