Johnny Estrada never caught on with the Mets. Acquired last month in a trade with Milwaukee, Estrada was let go Wednesday when the Mets declined to offer him a contract for next season. Coming off knee and elbow operations, the slow-footed catcher was shipped to New York on Nov. 20 in a deal that sent reliever Guillermo Mota to the Brewers. But only 10 days later Estrada became expendable when the Mets traded for another catcher, defensive standout Brian Schneider from Washington.