SAN FRANCISCO -- The Mets delivered a lesson in comportment following Wednesday's game. After rookie Jordany Valdespin showed up to AT&T Park in a plain white T-shirt, violating the club's self-imposed dress code, his teammates cut tassels into the sleeves and wrote messages on the shirt, scrawling "El Hombre" -- "the man," in Spanish -- in large block letters on the back.

Visibly angry at the time of the incident, Valdespin had calmed down by the time he left the ballpark. A day later, showing up in a pink, collared shirt, he said he understood the lesson.

"That's funny," said Valdespin, who wore the altered shirt around the clubhouse pregame Thursday and planned to keep it. "At the time you get mad, but what can I do? I'm not going to fight with anybody in here. We're a family in here. Sometimes they do it to be happy, have fun."

Valdespin came to the Mets this season with a history of immaturity on and off the field, concerning team officials. But he has mostly kept to himself during his rookie season, and manager Terry Collins said that Valdespin has done nothing to unsettle the clubhouse culture. Collins went as far as to absorb blame for the T-shirt incident, saying he never explained the dress code to Valdespin.

"He thought it was OK to wear a white T-shirt to the ballpark," Collins said. "This is the big leagues. So the guys said, 'No, we dress nicer than that.' They made the message."

Collins joked that if Valdespin was upset about the shirt, the Mets would be happy to dip into a "slush fund" to replace it. More important, Collins said, was that the Mets demonstrated the ability and willingness to police themselves in the clubhouse -- not necessarily a given on a young team.

But had roles been reversed, Valdespin said, he would have taken a different tact.

"I would never do that," Valdespin said. "You know why? Because you've got to respect everybody. The example here is this guy, David Wright. He's the captain of the team. He respects everybody."

Santana set for second bullpen on Sunday

SAN FRANCISCO -- Johan Santana threw his first full bullpen session Thursday since landing on the disabled list last month with a sprained right ankle. Santana is scheduled to throw another bullpen on Sunday, before returning to the Mets during their homestand next week.

Though Collins was not ready to set a specific date for Santana's return, that schedule would put him in line to pitch Wednesday against the Marlins. The Mets will settle on a date once they see how Santana feels following his two bullpen sessions in Port St. Lucie, Fla.

"I absolutely do not [expect him to have any issues]," Collins said. "He's fine."

One byproduct of Santana's injury is that it has given him a lengthy midseason opportunity to rest his surgically repaired left shoulder. Collins said earlier this week that Santana's shoulder felt "great," which could pay dividends on the mound; since throwing the first no-hitter in franchise history June 1, Santana has gone 3-5 with a 6.54 ERA.

The Mets also must make a decision regarding when -- or whether -- to use R.A. Dickey on three days' rest, an experiment they have all but committed themselves to. How the team uses Dickey in August will have a significant impact on Santana and the rest of the rotation.

Worth noting

• Frank Francisco plans to meet the Mets in San Diego, where he will come off the disabled list in time for Friday's series opener. Francisco will immediately step back into the closer's role, ending Bobby Parnell's six-week run with the job. Regardless, manager Terry Collins said that Parnell will continue to see stray save opportunities if Francisco has worked multiple days in a row.

• Andres Torres returned to the starting lineup Thursday following a two-game absence with a bruised right thumb. Collins said the switch-hitting Torres may still have issues batting left-handed, but was fine to start Thursday against lefty Barry Zito. Torres, who appeared in the ninth inning Wednesday as a defensive replacement, is also fine to play in the outfield.