The field of competitors for the sole Western Massachusetts casino license will soon expand with the addition of Hard Rock International, which is expected to announce a deal Friday to pursue development rights at the Eastern States Exposition fairgrounds in West Springfield, home of The Big E agricultural fair.

Eastern States Exposition, a nonprofit institution, has scheduled a “red carpet” luncheon Friday for a casino-related announcement. It did not release any details, though several sources said the organization has reached a deal to move forward with Hard Rock on a ­casino resort. Hard Rock representatives have visited the site many times, after exploring bids in Holyoke and Springfield in 2012.