Park had appeared in 29 games for the New York Yankees this season, surrendering 22 earned runs on 40 hits with 29 strike outs. The Yankees designated the 37-year-old South Korean right-hander for assignment Saturday.
Pittsburgh becomes the seventh different team Park has played for since entering the major leagues in 1994.
Resop has spent most the season in the minors and has made only one Major League appearance since 2008.
(Writing by Steve Keating in Detroit, Editing by Greg Stutchbury)