MIAMI -- Putting together a healthy infield is becoming increasingly difficult for Marlins manager Ozzie Guillen.

Third baseman Nick Green was scratched from the lineup Monday about three hours before the Marlins opened a three-game set against the Phillies. Guillen said Green injured his left thumb while making an attempt at a ball down the third-base line in Sunday's loss to the Dodgers.

"He stretched his thumb when he was making a play at the line, almost like [Emilio] Bonifacio did but not that bad," Guillen said. "He's just so sore, he can't close his hand."

Green was scheduled to have an X-ray taken of the hand Monday afternoon. The team will then decide if the career journeyman needs to be placed on the disabled list.

With Green out of the lineup, Guillen went with Greg Dobbs at third. Dobbs has been dealing with a tight left oblique since Saturday, when he was scheduled to start but was scratched from the lineup just before first pitch.

Guillen isn't sure how healthy Dobbs is, but was forced to test the veteran's oblique because of limited options available in the infield. Since the Marlins traded everyday infielders Omar Infante and Hanley Ramirez, the team has had injuries to four other infielders.

Donnie Murphy, who started five games at third base from July 29 to Aug. 3, is on the disabled list with a strained left hamstring. Bonifacio, who moved to second base following the Infante trade, has been sidelined with a strained left thumb since Aug. 4. Bonifacio is scheduled to start a rehab assignment with Class A Jupiter on Wednesday, and he said he will play center field for the Hammerheads -- a move Guillen hinted at during the weekend -- leaving the Marlins short another option in the infield.

With so many players coping with injuries and the Marlins running out of options at third base, Guillen said the team's emergency third baseman is outfielder Justin Ruggiano.

Ruggiano hasn't played third base during his Major League career, and his only professional experience at the position was for one game in 2010 when he was playing for Triple-A Durham.

"That's my best choice," Guillen said. "Who do you think I should play at third base? Hopefully, Dobbs is available to play."

Catcher Brantly set for big league debut Tuesday

MIAMI -- When Rob Brantly was traded to the Marlins in a package that sent Anibal Sanchez and Omar Infante to Detroit, the 23-year-old backstop was optimistic about the opportunity at hand.

On Tuesday, that opportunity will be to make his Major League debut. Manager Ozzie Guillen said Brantly, who is the Marlins' No. 13 overall prospect, will start behind the plate against the Phillies and righty Kyle Kendrick.

"There's going to be a lot of excitement, maybe a little butterflies, but I'm just trying to take it as business as usual," Brantly said.

The Marlins' plan for Brantly, whose contract was selected from Triple-A New Orleans on Monday, is to get him plenty of playing time and plate appearances in order for the team to evaluate whether he is prepared for the Majors or if he needs another season to develop, Guillen said.

The team's desire to see what Brantly is capable of could mean a platoon at catcher with John Buck for the remainder of the season. Guillen wants to meet with Buck before deciding how to handle the situation.

Guillen said he has received good reports on Brantly, who hit .365 with a .389 on-base percentage, four doubles, two homers and 11 RBIs in 14 games for New Orleans.

"One thing he needs to work on a little bit is the defense," Guillen said. "But they say he swings the bat pretty good and has a chance to be a good player. We'll see pretty soon how good he can be."

Buck has struggled for much of the season, but seems to have turned it around this month, hitting .333 (10-for-30) with seven doubles in August entering Monday.

Regardless of how the situation plays out, Buck said it's his duty to mentor Brantly and help him acclimate to the pitching staff.

"He's a young guy, but even if it was a catcher with experience coming in, we'd go over exactly what our pitchers do, what are our strengths, weaknesses," Buck said. "If there are any of those things that are obviously part of the catcher's job to relay to the backup, or the other catcher, of course I'll do that."