PHOENIX -- With Luis Castillo's activation from the disabled list Monday, the final puzzle piece clicked into place for the Mets. For the first time in over a year, their lineup was complete.

That much was made possible by Castillo, who officially returned to the active roster Monday following a six-week DL stint with a bruised right heel. Castillo, who played second base Monday and batted eighth, wore orthotic inserts in both shoes.

"When I went on the DL, I thought it would take like two weeks and that would make me feel better," said Castillo, whose troubles with his left foot ultimately affected his right one. "I had to take the time when I had to take it. I feel good right now. That's why I'm here."

To make room for Castillo, the Mets optioned infielder Ruben Tejada to Triple-A Buffalo. Because they envision Tejada as an everyday player, the Mets prefer for him to receive consistent at-bats in the Minors rather than sporadic ones in the Majors.

Tejada hit .212 in 104 at-bats with the Mets, providing strong defense at both shortstop and second base.

He was, however, just a fill-in. Castillo is a regular. So is shortstop Jose Reyes, who was back in Monday's lineup after missing the last five games with a strained right oblique. And so is center fielder Carlos Beltran, also back in Monday's lineup after a routine off-day Sunday.

Castillo, Reyes, Beltran and third baseman David Wright had not all been in the same lineup since May 20, 2009. The Mets had not fielded a full lineup of first-string players since April 13, 2009.

And so Monday, for the first time in more than 15 months, they were complete.

"The tough thing is that it's July and they're just getting on the field," manager Jerry Manuel said. "I know they're all going to have some adjustments to make, but I think the good thing is that for the most part, they should be fresh. They should be hungry to play. You're just like anybody else, you're kind of anxious to see how that looks."

Mets keen on monitoring Perez in Arizona

PHOENIX -- Oliver Perez is scheduled to arrive in Arizona on Tuesday. That does not, however, mean that the Mets are ready to activate him.

Pitching coach Dan Warthen and his staff will watch Perez throw at Chase Field before determining whether he is ready to be activated from the disabled list, where he has resided since June 5 with a bout of right knee tendinitis.

"They know him better than anybody," assistant general manager John Ricco said of Warthen and his staff. "These guys will see him and see what he looks like and if he's ready to come off [the disabled list]."

Perez was moderately successful in his most recent rehab start with Triple-A Buffalo, striking out seven over 6 2/3 innings. But he also allowed three runs, walked two and sat in the mid- to high-80s with his fastball velocity.

With his consent, the Mets can keep him on Minor League rehab assignment through July 29. But they believe Perez, if healthy, can help their bullpen, and so the Mets could activate him as soon as this week.

"Right now, all our focus has been to get him back here and pitching for us," Ricco said. "Based on the fact that he's had four starts and he's progressing, we're optimistic that he's going to be ready to go with us here shortly."

Matchups lean in favor of Pagan getting starts

PHOENIX -- Without trying to, the D-backs are forcing Jerry Manuel's hand in right field.

By starting three consecutive right-handers this week at Chase Field, the D-backs will force Manuel either to stick with switch-hitter Angel Pagan as his regular right fielder, or give some at-bats to the right-handed Jeff Francoeur. Based on the recent play of both, Pagan seems to be the clear choice to receive the bulk of the playing time -- and he was indeed the choice to start Monday's series opener.

"He's played extremely well," Manuel said. "You've got to give Angel every opportunity now."

Any opportunity for Pagan, however, will come at the expense of Francoeur, who is quickly becoming a well-paid fourth outfielder. He could still steal a few at-bats if Carlos Beltran cannot play every day, but otherwise, Francoeur is in danger of descending into a pinch-hitting role.

For someone who has been an everyday player throughout his six-year career, a severe downtick in playing time could be difficult to swallow. But Francoeur entered Monday's play hitting .246 overall and just .122 in July.

Ump's late calls 'frustrating' to Manuel

PHOENIX -- Despite the Mets' displeasure with home-plate umpire Phil Cuzzi during Sunday's ninth inning in San Francisco -- and despite catcher Henry Blanco's pointed comments following the game -- the team will not pursue punitive action against Cuzzi and his crew.

"Yesterday was frustrating," manager Jerry Manuel said Monday afternoon. "I do think that Major League Baseball, when things like that do happen, I'm sure they have some type of discussion with the umpire. What they do or what they say, that's really up to them."

The Mets did come out on the right end of Cuzzi's most egregious ruling, calling Travis Ishikawa out at the plate with what would have been a game-winning run. Replays clearly showed that Ishikawa was safe.