If anyone had told Clay Buchholz back in April that all of Red Sox Nation would be relying on him to resurrect the Red Sox from an 0-2 deficit to the Angels in the ALDS, chances are he would not have believed them. When the right-hander began the year with Triple-A Pawtucket, little did he know that he would hold the fate of the 2009 Sox season in his hand.

After aces Jon Lester and Josh Beckett failed to deliver wins in their respective outings, the Red Sox look to Buchholz (7-4, 4.21) to keep their postseason run alive as he makes his first career start in the playoffs. Treading on the brink of elimination, the Sox need Buchholz to turn in his best performance since he pitched a no-hitter in his second career start on Sept. 1, 2007. With the Sox managing to accumulate only one run in 18 innings, Buchholz cannot be certain that he will receive a decent amount of run support, adding to the pressure that every pitch could decide the outcome of the game.

When Daisuke Matsuzaka and Tim Wakefield were placed on the disabled list and free agent signings Brad Penny and John Smoltz both fell short of meeting expectations, Buchholz emerged as a pleasant surprise for the Red Sox. Though he struggled in his first few starts after being promoted from Triple A, the Texas native was stellar in September, going 4-1 in six starts with a 2.87 ERA.

Buchholz faltered in his last two starts, surrendering 13 runs in 11 innings, including six home runs. In his career opposing the Angels, Buchholz has not fared much better, owning a 1-2 record with an exorbitant 6.35 ERA. Angels outfielder Vladimir Guerrero has hit particularly well against the right-hander, collecting four hits in nine plate appearances.

On the flip side, Scott Kazmir (10-9, 4.89) returns to the postseason for the second consecutive year. Though he now dons an Angels jersey instead of a Rays uniform, Kazmir has posted a 1-1 record with a 4.21 ERA in five career playoff starts. In the 2008 ALCS facing the Red Sox, the left-hander gave up a total of five earned runs in 10-1/3 innings over two starts — both of which resulted in no-decisions.

Spending a portion of the season on the DL, Kazmir had difficulty finding consistency while with the Rays, posting an 8-7 record and a hefty 5.92 ERA in 20 starts. After being dealt to the Angels on Aug. 28, Kazmir was rejuvenated, going 2-2 with an impressive 1.73 ERA in six starts.

Against the Red Sox, Kazmir has made 23 career starts, recording an 8-7 record with a 3.59 ERA. While many Red Sox batters have seen little success against the left-hander, second baseman Dustin Pedroia has hammered Kazmir, batting .517 with three doubles, one triple, and one home run in 36 plate appearances.

With the season on the line, the Red Sox have no room for error. Returning to Fenway, where they compiled the second-best home record in the majors, the Sox look to recapture the come-from-behind magic that allowed them to overtake the Yankees in the 2004 ALCS.

Here is how both pitchers have matched up against Sunday’s opposing batters:

Clay Buchholz vs. Angels batters

Chone Figgins (9 career plate appearances) 2-for-6, 3 walks, 1 strikeout

Vladimir Guerrero (9) 4-for-9

Jeff Mathis (8) 1-for-5, 2 walks, 1 strikeout

Torii Hunter (6) 1-for-5, 1 walk

Maicer Izturis (6) 1-for-4, 1 double, 2 walks, 1 strikeout

Bobby Abreu (5) 1-for-5, 1 home run

Howie Kendrick (5) 1-for-5, 1 strikeout

Juan Rivera (5) 0-for-5, 2 strikeouts

Erick Aybar (3) 0-for-3

Gary Matthews, Jr. (3) 0-for-3, 2 strikeouts

Robb Quinlan (3) 1-for-3, 1 home run, 1 strikeout

Reggie Willits (3) 0-for-3, 2 strikeouts

Scott Kazmir vs. Red Sox batters

David Ortiz (50 career plate appearances) .205 AVG, .300 OBP, .364 SLG, 1 double, 2 home runs, 6 walks, 11 strikeouts

Mike Lowell (45) .250, .333, .600, 2 doubles, 4 home runs, 4 walks, 10 strikeouts

Kevin Youkilis (45) .237, .333, .316, 3 doubles, 6 walks, 14 strikeouts

Jason Varitek (44) .188, .386, .313, 1 double, 1 home run, 9 walks, 11 strikeouts

Dustin Pedroia (36) .517, .600, .793, 3 doubles, 1 triple, 1 home run, 6 walks, 1 strikeout

Jacoby Ellsbury (20) .300, .300, .350, 1 double, 2 strikeouts

Jason Bay (17) .267, .353, .533, 1 double, 1 home run, 2 walks, 6 strikeouts

Victor Martinez (11) 5-for-11, 1 strikeout

Alex Gonzalez (10) 4-for-10, 1 double, 2 strikeouts

Brian Anderson (8) 0-for-6, 2 walks, 5 strikeouts

J.D. Drew (8) 1-for-7, 1 triple, 1 walk, 3 strikeouts

Jed Lowrie (7) 0-for-3, 4 walks

Casey Kotchman (5) 2-for-5, 1 double, 1 strikeout