The Terps struggled with draw controls in back-to-back losses to No. 2 Northwestern.
All three are ranked among Inside Lacrosse's top 40 recruits in their class.
Griffin was the team's leading goal scorer and preseason Big Ten Player of the Year in 2020.
In six games this past season, Hartshorn led the team in points, assists and draw controls.
Schettig leads the Terps in ground balls (17), is tied for the team lead in caused turnovers (9), and has won the second most draw controls (16).
The Terps rank just 50th in draw control percentage and 80th on free-position chances.
"All three of our goalies are great contenders and can go on the field and be great."
Warther ranks in Maryland's top five for goals, assists, ground balls, caused turnovers, and draw controls.
Florida midfielder Shannon Kavanagh notched eight goals in the upset.
Meghan Doherty, Brindi Griffin, Grace Griffin and Kali Hartshorn are earned the preseason nod.