The initial lure of interleague play in Major League Baseball was the opportunity to see regional rivals from different leagues finally play each other...

The initial lure of interleague play in Major League Baseball was the opportunity to see regional rivals from different leagues finally play each other in the regular season. But annual home-and-home matchups — and the regular sellouts that accompanied many of those games — may be on the way out due to league realignment next season.

ESPNNewYork.com reported last week that MLB’s schedule-makers expect to pull the plug on home-and-home interleague series between natural rivals (such as the New York Yankees and New York Mets, Chicago White Sox and Chicago Cubs, Los Angeles Angels and Los Angeles Dodgers and Oakland Athletics and San Francisco Giants) so that teams are freed up to play interleague games at any point in 2013.

Interleague play — which began in 1997 as a way to try and reignite baseball’s popularity with fans who were staying away from the park in droves after the players’ strike of 1994 killed the World Series — is presently limited to a weekend in May and two consecutive weeks in June, but with the Houston Astros moving to the American League West after this year, each league will have 15 teams. Unless MLB wants to have multiple teams off every day, it’ll be impossible to keep interleague play in its current window.

According to ESPNNewYork.com, the new arrangement would have natural rivals playing each other either once per season (in a three-game series) or in a pair of two-game series at each ballpark. Interleague opponents would still rotate by division, which would allow for each team to play another team twice per year. So natural rivals such as the Yankees and Mets would still play each other twice a season when the AL East and NL East played one another every third year.

The demise of twice-annual interleague series would be particularly bad news for teams such as the Mets and White Sox that have difficulty drawing despite their large market status. ESPNNewYork.com reported that the nine biggest crowds in the three-year history of Citi Field were for the Mets’ home games against the Yankees. The White Sox, meanwhile, drew more than 35,000 for just five of 81 home games last season, including all three games against the crosstown Cubs.

A search of StubHub today, May 9, reveals 3,578 tickets available for the opening game of the Yankees-Mets series at Citi Field Friday, June 22, the cheapest of which is a $59 Promenade Reserved seat. But tickets to the Mets’ next home game against the Milwaukee Brewers Monday, May 14 begin at a mere $8.75 for a Left Field Landing seat.

The overhaul of interleague play would not signify the end of a tradition everywhere. While series such as Yankees-Mets, Angels-Dodgers, and Athletics-Giants are fun for fans, there are also plenty of teams that have no natural rivals, which creates awkward twice-yearly series such as Seattle Mariners-San Diego Padres, Minnesota Twins-Milwaukee Brewers, and Detroit Tigers-Pittsburgh Pirates that don’t fuel anybody’s passions. Three Mariners-Padres games in Seattle last year, for example, drew average crowds of 24,805, a minimal increase over the Mariners’ average attendance of 23,412.