EAST BOSTON, Mass. – Suffolk Downs, the last surviving Thoroughbred track in New England, opens its 2014 meet Saturday under the warning that this could be its last.The track, which straddles the cities of East Boston and Revere, has partnered with gaming titan Mohegan Sun to develop a $1.3 billion resort casino on the Revere side of the grounds and is in heated competition with Wynn Resorts for the sole license designated for the greater Boston area. Steve Wynn’s proposed $1.6 billion casino development would be located in the city of Everett, just two miles from the stable gate, and Suffolk’s ownership group has said repeatedly that it cannot continue live racing unless Mohegan Sun wins the license.The track’s operating losses ranged from $11.8 million to $26.4 million over a five-year period, and the track’s handle has nosedived from $27.6 million in 2000 to $6.5 million in 2012, according to data filed with the Massachusetts Gaming Commission. In 2013, the state imposed a 5 percent surtax on gambling winnings in excess of $600, and that has further eroded handle.Despite the uncertainty, New England horsemen are returning from the East Coast tracks and area farms where they wintered. As of April 29, there were about 400 horses on the backside, with another 200 to 300 expected to arrive in the next few weeks.This year’s meet opens about a month earlier than in the recent past so as many live days as possible can be run before the gaming commission selects the casino licensee. The commission was originally scheduled to make the award in February but has pushed back the timetable several times due to procedural and political issues. The date is now “undetermined.”Track management and the New England chapter of the Horsemen’s Benevolent and Protective Association reached an agreement that live racing will be conducted through at least Sept. 1. Should the Mohegan Sun/Suffolk Downs partnership be awarded the license, the track has pledged to continue live racing for a minimum of 15 years, as required by law, and to implement a $40 million racing improvement plan that includes the restoration of the Massachusetts Handicap.After Opening Day, racing will be conducted on Wednesday and Saturday the first week, then Monday, Wednesday, and Saturday (Preakness Stakes Day) the following week. Beginning Monday, May 19, four-day race weeks (Monday, Tuesday, Wednesday, and Saturday) will be scheduled through the conclusion of the meet.There is an eight-race stakes schedule, all restricted to Massachusetts-breds, and each offers a purse of $50,000.