Devices and methods for placing an adjunct at a tissue treatment site prior to delivering staples through the tissue and adjunct are provided. In one embodiment, a flowable adjunct precursor can be deposited on the surface of the tissue at the tissue treatment site. The flowable adjunct precursor can be configured to solidify after deposition to form an adjunct. In another embodiment, an adjunct delivery device can include a non-stapling end effector configured to deliver an adjunct to a tissue treatment site. In either case, staples can be delivered through the adjunct and tissue after placement of the adjunct at the tissue treatment site.