Tony Clark, the head of the players' union, says baseball fans should question whether it makes sense to purchase tickets for some teams.

The comments were made in response to Rob Manfred's assertion that free agents have failed to adjust their economic demands in a market upended by analytics.

"Players' eyes don't deceive them, nor do fans'," Clark said. "As players report to spring training and see respected veterans and valued teammates on the sidelines, they are rightfully frustrated by a two-year attack on free agency. Players commit to compete every pitch of every at-bat, and every inning of every game. Yet we're operating in an environment in which an increasing number of clubs appear to be making little effort to improve their rosters, compete for a championship or justify the price of a ticket."

Average attendance has dropped for three straight seasons and last year fell below 30,000 per game for the first time since 2003.