The city of Oakland has mailed a letter to Athletics president Dave Kaval expressing concerns with the club's decision to block a minor league game by the expansion Oakland Ballers that had been scheduled for the Coliseum on June 29.

The A's will be on the road at the time the new minor league independent team wanted to host a special night at the venue.

The "B's" had a signed agreement in place for that date and a deposit paid when they learned late last month the big league team vetoed the plan without providing a reason.

Rebecca Kaplan, a council member at-large, and District 6 representative Kevin Jenkins mailed their joint letter Monday and asked for a prompt explanation.