The senior injured his left heel last month.
Haas led the Boilermakers with 20 points.
Cowan attempted a team-high 18 shots.
Anthony Cowan and Bruno Fernando impressed Tuesday.
The redshirt freshman set career highs in points, rebounds and minutes.
This was not a pretty win.
The Terps have struggled this season, but making it past the first weekend of the NCAA Tournament is something to be proud of.
The Terps play the Jackrabbits for a spot in the Round of 32.
The Cornhuskers upset No. 6-seed Wisconsin, 70-58.