By Tom Verducci The two sides need a deal by Feb. 28 to preserve the scheduled Opening Day March 31. Negotiators for Major League Baseball and the players association are scheduled to meet again Monday after a session Thursday lasted only 15 minutes and underscored the gulf between the sides and the paucity of actual negotiating. Starting Monday, the two sides will have one week to reach an agreement that preserves the scheduled Opening Day March 31. That timetable allows for two days for both sides to ratify an agreement and for a compressed spring training of 28 days. Neither the rate nor mo…