"There are some things that I've seen lately that have gone too far," Lynn said on MLB Network Radio, according to Jim Duquette, adding he's "never been on a team that has encouraged us to use it."
Recently, theScore's Travis Sawchik broke down the differences between pitchers using rosin, or a combination of rosin and sunscreen, versus using Firm Grip or Spider Tack. He found the latter substances resulted in a more substantial impact on spin rate.
Lynn, 34, is among a handful of pitchers so far to break their silence regarding MLB's issue with sticky substances affecting spin rates and seemingly reducing offensive production. Los Angeles Dodgers right-hander Trevor Bauer recently mentioned that foreign substances are a problem the league has swept "under the rug" for four years.
MLB has begun confiscating on-field items such as game-used balls from specific pitchers and hats, such as the one St. Louis Cardinals pitcher Giovanny Gallegos wore.
While no pitcher has been punished yet, the league reportedly plans to implement rules by June 14 that could lead to suspensions or fines for hurlers who use foreign substances.