I’m going to assume this is merely some going-through-the-motions review and not something that will lead to any actual discipline, but …
Major League Baseball has reviewed video of Jose Valverde apparently throwing a spitball and has discussed the incident with the Detroit Tigers, according to a source with knowledge of the situation.
Valverde and the Tigers have not been given an official warning, but MLB’s handling of the incident indicates a de facto warning.
Probably the best that can be done. A general “we’re watching you, buddy” from the league.