ATLANTA -- The Mets are certain of this: There is no certainty about their rotation this weekend in Miami. John Maine will pitch, Jorge Sosa probably will pitch. Orlando Hernandez might, and if he doesn't, Jason Vargas probably will. And the games each will start are undetermined. Got that?

Everything revolves around El Duque, who seemingly moved within 60 feet, six inches of returning to the rotation Tuesday when he threw what manager Willie Randolph termed "a good side-session."

The manager said "he came through it really well. We'll see how he feels tomorrow, and slot him in this weekend." Hernandez has been on the disabled list since April 25 because of bursitis in his right shoulder.

For now, Maine, who pitched Sunday night against the Yankees, is to start Friday on his normal four days' rest. Hernandez could pitch Saturday, and Sosa, who started against the Braves on Tuesday night, could go Sunday. If El Duque isn't ready to pitch. Jason Vargas could make his second start.

The uncertainty about Hernandez is such that Randolph said on Tuesday he was reluctant to use Vargas in relief because of the chance he will have to start in Miami.

New digs: The Mets broke ground on Tuesday on a $7.5 million international baseball training academy in Boca Chica in the Dominican Republic. Dominican president Leonel Fernandez, Mets chief operating officer Jeff Wilpon, general manager Omar Minaya and vice president Dave Howard attended the ground-breaking ceremonies. The academy is scheduled to open in April 2008.

The academy will have three fields, including one which will replicate the asymmetrical dimensions and wall height of Citi Field, the future home of the Mets that's scheduled to open in April 2009. The 37-acre complex will have a half-field, two bunting fields, four batting tunnels, five covered pitching mounds, a clubhouse, weight training rooms, a dining hall, classrooms, a computer lab and administrative offices. In addition, the complex will house 60 players, as well as the managers and coaches and accommodations for 16 tryout players.

The new academy will replace the Mets' current facility located in San Cristobal.

"We've established a presence in the Dominican Republic that is central to our player-development efforts," Wilpon said. "This new training complex reinforces our commitment to further expanding our operations on an international level and fortifies our investment in developing the best baseball players in the Majors.

"The state-of-art training academy is integral to attracting, signing, and fostering the development of the best talent in the Dominican Republic and Latin America," Minaya said. "This new academy creates a point of difference for our organization with a facility, education, and competitive center as we seek to find the next Pedro Martinez and Jose Reyes."

That date in Mets history -- May 23: Ray Sadecki, making his first start in 32 days (he made five relief appearances in the interim), pitched a five-hitter in the Mets' 4-0 victory at Shea Stadium on this date in 1971. ... Randy Jones, who pitched 11 shutouts in the 1975 and '76 seasons, pitched the 19th and final shutout of his career at the Astrodome on this date in 1982, allowing four hits and a walk. ... A third shutout by a left-handed Mets pitcher happened on this date in 1998. Al Leiter limited the Brewers to four hits and a walk in a 3-0 victory at Shea.

With John Olerud (two), Robin Ventura (two) and Jermaine Allensworth driving in runs, the Mets scored five runs in the ninth inning against Curt Schilling and defeated the Phillies, 5-4, at Shea on this date in 1999. Until last Thursday, when the Mets scored five times in the ninth to beat the Cubs, 6-5, no Mets team had matched the comeback against Schilling. ... Another Mets comeback happened on the same date a year later in San Diego. Mike Piazza hit a two-run home run against Trevor Hoffman in the 10th inning, and the Mets won, 5-3. The Padres had won 183 consecutive games in which they led entering the ninth inning. ... Jeromy Burnitz hit a grand slam off Russ Ortiz in a six-run rally in the sixth inning that carried the Mets to a 6-5 victory at Turner Field on this date in 2003. It was the Mets' 15th victory in 44 games at Turner Field.

Coming up: Left-hander vs. left-hander. Oliver Perez and Chuck James are the Mets' and Braves' respective starters in the 7:35 p.m. ET game at Turner Field on Wednesday.