NEW YORK -- Infusing some concern into this final homestand, Mets outfielder Carlos Beltran left Tuesday's game after five innings with right knee discomfort. Though he does not believe the injury is serious, Beltran, who underwent surgery on the same knee in January, will have an MRI Wednesday to determine its severity.

"I don't feel like I have to worry," Beltran said. "The pain that I felt last year, it bothered me to walk. It bothered me to do everything. I've been walking here, and I don't feel that sensation."

Reaching on an error in the fourth inning, Beltran felt pain for the first time as he led off first base. Though he played an additional inning in the field, Beltran alerted trainer Ray Ramirez to his condition shortly thereafter, prompting the Mets to remove him from the game.

"I have to be smart about it," Beltran said. "I just can't go out there feeling like that. It's not right."

There is reason for concern regarding Beltran, who underwent arthroscopic right knee surgery in January. Originally expected back by May, he did not wind up returning until the first game after the All-Star break. Since his return, Beltran has had no setbacks -- though he did sit out a game last month with tendinitis in his left knee -- a result of overcompensating during his recovery.

Beltran, 33, also underwent surgery on both knees prior to the 2008 season.

"This is the first time that we've really had an issue with that knee since he's been back," Mets manager Jerry Manuel said. "He's been pretty good for the most part."

After struggling on both offense and defense upon his return, Beltran had finally begun hitting with consistency in September, entering Tuesday's play batting .364 with five home runs over his last 17 games.

Now, his team may have to stall that momentum. With just six games remaining in the regular season, it seems unlikely that the Mets would allow Beltran to play again this year. But they will wait for the results of Wednesday's MRI before making any decisions.

"Honestly, in my heart, I don't feel like I have to worry," Beltran said. "I felt something. I don't know what it is. But after being back and being able to play all these games, I didn't feel anything until today. So let's see what happens."

Ollie unlikely to be used in spot start

NEW YORK -- The last call for Ollie is about to go unanswered.

With one final opening in his rotation this Saturday, Mets manager Jerry Manuel indicated Tuesday that left-hander Raul Valdes, and not Perez, will make the spot start.

"Valdes is probably the closest guy to being that guy right now," Manuel said.

Valdes is not all that much more stretched out than Perez, appearing in only six games in August and September combined, and last throwing 26 pitches in relief on Sept. 19. But the Mets have avoided using Perez ever since he returned from the disabled list in late July, last deploying him for a two-inning outing on Sept. 6.

Earlier this month, Manuel said that it "would not be fair to Oliver" to give him a spot start down the stretch due to the fact that his arm is not stretched out. And so the Mets will not, proceeding instead with Valdes.

In 35 relief appearances this season, Valdes is 3-3 with a 5.51 ERA. He was 2-1 with a 3.06 ERA in seven starts for Triple-A Buffalo earlier this summer.

Perez has one season and $12 million remaining on the three-year, $36 million contract he signed prior to the 2009 season.

Pagan, Warthen attend to family matters

NEW YORK -- Due to family issues, the Mets were without two uniformed employees for Tuesday's game against the Brewers.

Pitching coach Dan Warthen was en route to Jacksonville, Fla., for the funeral of his brother, David, who passed away earlier Tuesday. Warthen is expected to miss Wednesday's doubleheader at Citi Field, as well.

Outfielder Angel Pagan was also absent, spending time with his family in New York. Pagan's youngest daughter, two-year-old Briana, will undergo surgery early Wednesday morning to correct an issue called strabismus -- the inability to focus both eyes simultaneously. Pagan is due to return to the Mets following his daughter's operation, in time for Game 1 of the doubleheader.

Worth noting

The Mets announced that Jon Niese will pitch the first game of Wednesday's twi-night doubleheader at Citi Field. R.A. Dickey will start the nightcap. ... Handicapping the National League Rookie of the Year Award race, Mets manager Jerry Manuel said that if he had votes, they would go to outfielder Jason Heyward of the Braves, first baseman Gaby Sanchez of the Marlins and his own first baseman, Ike Davis. ... Seton Hall University men's basketball coach Kevin Willard and women's basketball coach Anne Donovan threw out ceremonial first pitches prior to Tuesday's game. The Mets Foundation will make a donation to Seton Hall in the name of 19-year-old student Jessica Moore, who was shot and killed at an off-campus party early Sunday morning.