PORT ST. LUCIE, Fla. -- Faced with the reality of his declining fastball velocity, Jason Isringhausen did something Thursday that he hadn't attempted in more than a dozen years.

During a live batting-practice session, Isringhausen uncorked a few changeups in addition to his usual array of fastballs, curves and cutters, attempting to add a fourth pitch into his arsenal.

"I think as your velocity drops, you need something to get them off your fastball," Isringhausen said. "Would it be my bread and butter? Not right now. But it could be. I've always told myself I can do anything with a baseball if I work at it."

Said manager Terry Collins: "It really had good life to it. With his arm speed, I think it would be very effective."

In Isringhausen's estimation, he hasn't regularly thrown a changeup since his last season as a full-time starter, way back in 1997. Since born again as a reliever, Isringhausen has focused his energies exclusively upon his fastballs, cutters and curveballs -- the latter being his primary out pitch.

Though he doesn't envision the changeup becoming a prevalent part of his repertoire, Isringhausen does plan to use it during games -- if for no other reason than to prove that he can throw it. No longer pitching regularly in the mid-90s, Isringhausen feels he needs to add an element of deception to his game, giving hitters something else to keep in the back of their minds.

"I just never needed it," Isringhausen said. "When you're throwing in the mid-90s, you don't need a changeup."

Visa issues continue to delay Paulino's arrival

PORT ST. LUCIE, Fla. -- The visa issues plaguing catcher Ronny Paulino kept him out of camp for a sixth straight day on Thursday, with no resolution in sight.

Paulino, who was due to report to camp last Saturday, continues to experience trouble entering the United States from his native Dominican Republic. The Mets originally expected him to arrive Monday or Tuesday, but those dates have long since passed.

"We've got a lot of time to get him ready," manager Terry Collins said. "He'll get his chance to catch. He can learn that fast."

As Collins noted, the absence should not affect Paulino's timetable -- he had already been scheduled to spend time in extended Spring Training come April, due to the eight games remaining on his 50-game performance-enhancing substance suspension.

Paulino, 29, inked a one-year, $1.3 million contract in December to serve as Josh Thole's backup behind the plate.

Beltran keeps up intensity of running program

PORT ST. LUCIE, Fla. -- The Mets' training staff wanted to decrease the intensity of Carlos Beltran's running program on Thursday.

Beltran said no chance.

Aiming to whip his surgically repaired right knee into game shape as quickly as possible, Beltran pressed forward by participating in baserunning drills Thursday, marking yet another progression in his rehab.

"That's a huge sign, because he told me when he starts running the bases, he'll be closer to playing," manager Terry Collins said.

Regardless, the Mets plan on holding Beltran out of the first week of Grapefruit League games, limiting him to designated-hitter duties once he does play. The team wants Beltran to work into shape before making a decision on their starting center fielder.

Worth noting

The latest victim of R.A. Dickey's knuckle ball was Angel Pagan, who showed off a bloody fingernail Thursday afternoon -- the product of a flailing swing against one of Dickey's midseason knucklers. "Nasty," Pagan said, referring to the pitch and not the fingernail. ... Manager Terry Collins expanded the scope of the second-base competition Thursday, saying that both Ruben Tejada and Chin-lung Hu have outside chances to win starting jobs. ... Collins heaped praise upon Nationals prospect Bryce Harper, who will travel to Port St. Lucie for a game on Monday. "Oh God almighty, that bat's special," said Collins, who watched Harper play last summer.