CHICAGO -- The Mets sleepwalked through their series opener at Wrigley Field despite a solid outing from Johan Santana and lost to the Cubs, 6-1, Monday night. Terry Collins generously called the Mets "flat." The skipper had expressed concern before the game about a post-Subway Series letdown, especially since the Mets arrived in the Windy City at 5:10 a.m. ET.

Tuesday's news reports:

• Assistant GM John Ricco tells columnist Ken Davidoff in the Post that the Mets will explore the trade market for relievers. "Our numbers are what they are," Ricco told Davidoff. "... It’s not too early to do the research. It’s probably too early to make a move, although each year there is several preemptive ones. For the seller more than the buyer.”

Davidoff goes on to list Houston's Brett Myers, San Diego's Huston Street, Oakland's Grant Balfour and Minnesota's Matt Capps (who just landed on the DL) as some of the best pieces potentially available. Davidoff notes that with a player traded midseason no longer yielding a draft pick for the acquiring team when he leaves after the season, teams may not be willing to offer as much. Then again, with two wild-card teams in each league now, there should be fewer sellers, potentially raising the asking price. With the Mets averse to giving up prospects, how much money the Amazin's would be willing to kick in to a deal might be the determinative factor. Writes Davidoff:

Myers is making $11 million this season and has a $3 million buyout on his $10 million vesting option, which he’s on track to hit (reportedly with 45 games finished). Balfour earns $4 million this year, with a $350,000 buyout on a $4.5 million team option for next year. Street has a $7.5 million salary and a $9 million mutual option for 2013 with a $500,000 buyout. General manager Sandy Alderson hasn’t ruled out the possibility of taking on payroll. He also told The Post two weeks ago, when discussing the Mets’ immediate needs, “We have to sort of take everything into account,” which means that the Mets won’t be dealing top-shelf prospects for volatile relievers. Hence the need to spend money so they won’t spend prospects.

For sure, the Mets will look beyond just the big names, try to find arms that wouldn’t cost much of anything. “Sometimes,” Ricco said, “you try to catch lightning in a bottle,” and he referenced the Mets’ acquisition of Guillermo Mota from the Indians in 2006. “That was a deal when they were just giving him away.”

• Read game recaps in the Star-Ledger, Post, Record, Times, Newsday and Daily News.

• Bobby Parnell will serve as the closer during Frank Francisco's stint on the disabled list for a strained left oblique. Read more in the Star-Ledger, Post and Record.

• Jason Bay was cleared to begin physical activity Monday. The first step was to ride a stationary bicycle. If concussion symptoms do not recur, he will run midweek and begin baseball activities during the weekend.

• How big is the disparity between the performance between the Mets' starting pitchers and relievers? Nearly historic. Writes Michael Salfino in the Journal:

Mets starters, entering Monday's action, have effectively shut down hitters, compiling a 3.55 earned run average that's fourth-best in the league. But when the relievers are on the mound, that ERA rises to a major league-worst 5.22. The differential of 1.67 runs is second most since 1961, exceeded only by the 1980 A's (1.81). League-wide in 2012, relievers have an ERA about a half-run better than starters (3.63 to 4.14).

• The Mets had a modest bullpen tweak before the series opener in Chicago, adding a second left-hander, Justin Hampson. He made his Mets debut with a scoreless eighth despite allowing a triple. Read more in Newsday.

• Josh Satin went 4-for-5 with two homers but Buffalo lost, while Zack Wheeler benefited from gaudy run support from his Binghamton teammates and received a win despite allowing five runs, the most in a game since he was acquired by the organization. Read Monday's full minor league recap here.

• R.A. Dickey discusses former Penn State coach Jerry Sandusky's conviction in the Daily News.

• The phrase, "Welcome to the Friendly Confines of Wrigley Field" does not exactly extend to visiting players, who deal with cramped quarters in the historic ballpark. Writes Brian Costa in the Journal:

The clubhouse, which was last renovated in 1990, is more notable for what it lacks than what it offers. There is no cafeteria, no TV lounge, no video room and no couches. The only indoor batting cage is under the bleachers in right field. And while players are free to use the Cubs' weight room, the visiting clubhouse offers only a stationary bike.

TRIVIA: Highly regarded first-base prospect Anthony Rizzo is due to make his Cubs debut Tuesday. He originially was drafted by Boston, before being sent to San Diego and then Chicago. Which player went to the Red Sox when the Padres acquired Rizzo?

Monday's answer: Craig Brazell and Victor Diaz homered for the Mets in the Sept. 25, 2004 game at Shea Stadium that dealt a critical blow to the Cubs' playoff chances.