ATLANTA -- Jason Bay began a rehab assignment with Class A St. Lucie on Saturday night, and Mets manager Terry Collins expressed hope that the outfielder might be ready to rejoin the team as early as Tuesday for the series opener against the Astros.

Bay played six innings in left field for St. Lucie against Charlotte and went 1-for-2 with an intentional walk. The hit was a single.

Bay, sidelined since late March because of a strained ribcage, played in an extended spring game Friday, going 0-for-2 and drawing a walk. That cleared him to join the St. Lucie team for Florida State League games against Charlotte on Saturday and Ft. Myers on Sunday.

"We'll see where we're at after that," Collins said. "He's been swinging, he's been hitting, he's been running. He's done everything. Now it's just game at-bats."

Asked if the two games with St. Lucie would be enough to get Bay ready to return to the Mets on Tuesday, Collins said, "Ideally. In a perfect world, yes."

Bay hasn't played in a regular-season game since late July 2010, when he suffered a concussion crashing into the left-field wall at Dodger Stadium. His first season with the Mets had already been a disappointment, with the right-handed hitter batting just .259 with six homers in 95 games.

Emaus gets playing time vs. hometown team

ATLANTA -- Brad Emaus was drafted by the Braves in 16th round of the 2004 First-Year Player Draft, but decided to go to Tulane University rather than sign with his hometown team.

The second baseman got to play at Turner Field anyway on Saturday, as a member of the Mets.

It might be make-or-break time as a regular for Emaus, who was taken by the Mets from the Blue Jays in the Rule 5 Draft.

David Murphy started three consecutive games at second base early this week, and Emaus took just a .200 average and one RBI into the first game of Saturday's doubleheader with Atlanta. But New York manager Terry Collins promised to give the graduate of nearby East Coweta High School plenty of playing time against the Braves.

Emaus has to be offered back to Toronto, which took him in the 11th round after three years at Tulane, for half the Rule 5 Draft claiming price of $50,000 before he can be sent to the Minors by the Mets this season.

"When Brad Emaus made this club, there were some things discussed, and one of them was to give him a legitimate chance," Collins said before Friday night's game was rained out. "Putting him in and out of the lineup, we're not going to get answers out of that."

Mets prospect Martinez back on DL

ATLANTA -- Oft-injured Mets outfield prospect Fernando Martinez had to go on the seven-day disabled list with Triple-A Buffalo on Friday because of a tight right hamstring. He was 4-for-5 with a double in the Bisons' opener on April 7, but he hadn't played since Monday.

Martinez, 22, has never played in more than 90 games in any of his five professional seasons because of knee, lower back and hamstring problems. He appeared in the 2007 and '08 All-Star Futures Games, and was MVP of the 2010 Caribbean Classic, verifying his top prospect status when healthy.

The native of the Dominican Republic appeared in 75 Minor League games and seven with the Mets a year ago after playing in 45 games with Buffalo and 29 with New York in 2009. In his 109 Major League at-bats, he has a .174 average with a homer and 10 RBIs.

Martinez appeared in 10 Grapefruit League games for the Mets this spring, batting .364 with a homer and four RBIs in 22 at-bats. He tantalized the team even more in 2010, hitting .383 in Spring Training.