SAN FRANCISCO: Since the All-Star break, or maybe even before that, the Mets have suffered from a team-wide slump.

Every team goes through them. Just ask the Phillies, who went through something similar from late May through early June.

The Mets even swept the Phillies at Citi Field in May, shutting them out in all three games.

The Mets came within three innings of being shut out three straight games to the same opponent for the first time in their history.

They finally scored in the seventh inning last night, when Ike Davis clubbed a two-run home run into McCovey Cove.

The Mets would go on to score four runs in the game, losing, 8-4, but this time it was the pitching that let them down.

Hisanori Takahashi, filling in for the stiff-necked Mike Pelfrey, allowed six runs in 2.2 innings, putting the Mets offense in a deep hole. So right now, everything is going wrong, and the whole team is in a slump.

Oliver Perez made another rehab start last night, and pitched effectively, but who knows if it was effective enough for him to be recalled.

No matter what, the Mets are almost in a must-win situation today, needing to fly to Arizona on a positive note. The Phillies came back to beat the Cubs yesterday, so the Mets are now in third place, behind them in the NL East.

It has been said time and time again, but today’s game is the type that Johan Santana was brought here for.

The last time the Mets were in a “must-win” situation, the final game before the break, Santana was on the mound against the Braves and got the job done.

One week ago today, July 11, Santana shut the Braves out over seven innings on five hits, lowering his ERA a tad below three.

The Mets won that game, 3-0, to pull within four games of the Braves, and are now five games back.

The shame of it is, the Braves actually lost two straight home games to a bad Brewers team, but the Mets couldn’t take advantage either time.

This time, Santana better be on his “A” game, just like he has been over his last three starts.

The last time Santana pitched against the Giants at AT&T Park on May 16, 2009, he got rocked. In seven innings he allowed six runs (four earned) on 11 hits, but the Mets won the game, 9-6.

Santana will try and pitch the way R.A. Dickey and Jon Niese pitched in this series, allowing a combined two runs.

Pitching for the Giants will be fourth starter, and a good one, Jonathan Sanchez, who is having the best season of his career.

He has been compared throughout his career to Oliver Perez. A left-handed pitcher who  is inconsistent, with control problems.

Last season in 163.1 innings, Sanchez walked 88 batters. That’s a ratio of one walk every 1.9 innings.

This season, although he’s having a good one, his ratio of walks-to-innings pitched is 1.9 again. He has walked 53 batters in 103.2 innings pitched.

If the Mets want a reason to think they may be catching him at the right time, he has slumped of late, allowing five runs in two of his last three starts, with his last one coming against the Nationals.

The Giants did win the game, 10-5, and that day, July 10, was the one-year anniversary of the no-hitter he threw. When on his game, Sanchez does have no-hit stuff.

He’ll have some advantages in this game, too. The Mets will be without both Jose Reyes (oblique), and Carlos Beltran (rest) today, so it’ll be a below-average lineup that will also include catcher Henry Blanco.

Manager Jerry Manuel did say before last night’s game that Reyes “for sure” will be in Monday night’s lineup.

The Mets less-than-stellar lineup will include: Justin Turner, Jeff Francoeur, and Blanco.

It’s a game the Mets have to try any way possible to win. They’ll hope that Santana can shut down the Giants, so that they can at least scratch out enough runs to fly to Arizona with a win on the road trip.

Johan Santana vs. San Francisco (May 8)
ND, 7.2 IP, 4 ER, 8 hits, 0 BB, 6 SO

Jonathan Sanchez vs. New York (May 7)
ND, 7 IP, 4 ER, 7 hits, 1 BB, 3 SO, 3 HR*

*Two of them to Ike Davis

2010 season series (New York vs. San Francisco)

May 7: New York 6, San Francisco 4
May 8: New York 5, San Francisco 4 (11)
May 9: San Francisco 6, New York 5

July 15: San Francisco 2, New York 0
July 16: San Francisco 1, New York 0
July 17: San Francisco 8, New York 4

Giants lead series 4-2

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