Group of 45 adolescent looking for recs before baseball game [Detroit]
We used to take youth hockey teams into Nikki's (Bricktown/Greektown) for pizza and salad before Red Wings games. Not saying it's the greatest food ever but it is palatable, they do a nice job and can accommodate fairly large groups on a time schedule.
Assuming you're talking daytime on a date late enough in May that eating outdoors would work, I like Z's Villa. Actually I like it more for the place itself, the grounds and their great shuttle service to Downtown and Midtown events than I do for their food. I think they do fine with deep fried anything, but sauteed items exit the kitchen swimming in way too much oil.
They definitely have room for a group that size outdoors, and probably in their upstairs room as well. They also cater, so the group size shouldn't bother the kitchen.