Seattle’s T-Mobile Park may not be hosting baseball games any time soon, but starting Monday, it will be a place where people can go to donate blood.

Bloodworks Northwest will be hosting a pop-up blood donation site at T-Mobile Park’s Ellis Pavilion for at least the next three weeks. Each donor will get two tickets to a Mariners game of their choice in 2020--or, if there’s no season this year, in 2021.

“We’ll go and set up our equipment, keep it there, and it really becomes like a pop-up restaurant or a pop-up retail space where it’s going to be open for four weeks, maybe more,” said Bloodwork's Northwest's Vicki Finson.

In addition to the T-Mobile site, Bloodworks Northwest will open pop-up sites in Renton and Redmond.

This comes at a time when the region’s blood supply is running low.

More than half of blood donations used to come from mobile blood drives in churches, schools, and the blood drive bus. But churches and schools are closed, and the bus is too small to keep donors six feet from each other.