Filling in for the injured Daisuke Matsuzaka, Justin Masterson will make his first start of the season against the Orioles. Currently second in the AL in on-base percentage, the Orioles' offense is off to a quick start, so Masterson will be tested. Monday will also see the major league debut of Jordan Zimmermann, the top Nationals prospect and one of the top pitching prospects in the majors. He's expected to provide youth and potential to a team in dire need of it, but he gets a stiff welcome against Derek Lowe and the Braves. In the NL Central, Bronson Arroyo looks to go to 3-0 as he faces Mike Hampton of the Astros, who has a surprising 2.45 ERA in his first two starts.
Starting pitcher rankings for Monday, April 20 (* all stats listed are from 2008)
Rk.: The author's ranking of that pitcher for that day only. T: pitcher throws left-handed or right-handed. Record: pitcher's win-loss record. ERA: pitcher's earned run average. WHIP: pitcher's average number of walks plus hits surrendered per inning. K/9: pitcher's average number of strikeouts per nine innings. OPSA: pitcher's on-base plus slugging percentage surrendered to opponents. OPS: pitcher's opponent's composite team on-base plus slugging percentage. CT%: pitcher's opponent's success rate putting the ball in play (versus striking out).
Selected notes: As a starter last season, Justin Masterson had problems giving up the free pass, allowing 28 walks in 54 innings. He had his command in relief of Matsuzaka last Tuesday, but the Orioles are a much better offensive team than the A's. It's also worth noting that Masterson has pitched more than six innings just twice and has never reached seven, and that moving him from his middle-relief role serves to weaken the bullpen and his chances for a win. If Jordan Zimmermann can keep his walk rate to modest levels, he should have immediate success, although his outfield defense is a concern. The Braves, his first opponent, are off to a slow start offensively, and their best player is nursing a thumb injury. Facing Derek Lowe minimizes the chance to pick up a win, but Zimmermann should be buffered by his home park and his strikeout potential. The Astros have had Bronson Arroyo's number; he has a 5.82 ERA in his past 11 starts, with a particular problem of giving up the long ball (11 home runs in 68 innings). It doesn't help that Lance Berkman, Miguel Tejada and Carlos Lee are a combined 33-for-93 (.354) with seven home runs against him. Dealing with Mike Hampton is inherently risky, but with 13 strikeouts in his first two starts and a home date against a slumping Reds offense, he looks like a good spot start on a light slate of games. It also helps that his counterpart is liable to cough up enough runs to give Hampton a good chance at a win if he pitches well.
• Adrian Gonzalez, 1B, Padres: Three of his five hits against Jamie Moyer have gone out of the park; overall, he is 5-for-15 versus Moyer.
• Hunter Pence, OF, Astros: One of many Astros who does particularly well against Bronson Arroyo, Pence is 5-for-15 with three doubles, a triple, and two walks against the Reds' starter. With success like that, it's just a matter of time before he takes Arroyo out of the park.
• Conor Jackson, 1B, Diamondbacks: Jackson has faced Jason Marquis only 11 times, but three of his four hits have gone for extra bases, including two home runs. This is especially notable considering Jackson doesn't hit for much power.
• Chris Young, OF, Diamondbacks: The all-or-nothing hitter has been good for it all versus Marquis, launching three home runs -- his only hits -- in nine at-bats while striking out only once.
• Jason Varitek, C, Red Sox: While Varitek has hit southpaws better than right-handers in his career, he's yet to figure out Mark Hendrickson, against whom he's 3-for-16 (.188).
• David Ortiz, DH, Red Sox: Has just four singles in 19 at-bats against Hendrickson, which are matched by his four strikeouts.
• Adam Dunn, OF, Nationals: You can safely sit him against Derek Lowe, who has dominated Dunn, allowing one single in 13 at-bats and striking him out five times.
• Ryan Zimmerman, 3B, Nationals: Has had some success when he's made contact against Lowe, with a home run and a double among his four career hits against him, but eight strikeouts in 20 at-bats -- and Lowe's not even a strikeout pitcher -- tells a more complete story.
• Jason Giambi, 1B, Athletics: Is hitting a respectable .280 (7-for-25) against Andy Pettitte, but the other parts of his game suffer, with a paltry .296 OBP, a .400 slugging percentage and five strikeouts in those 25 at-bats.
If you're hardcore
• Mark Ellis, 2B, Athletics: Has more favorable splits against left-handers and is 6-for-12 with two doubles versus Andy Pettitte.
• Kevin Kouzmanoff, 3B, Padres: Hits .281 away from Petco Park and .285 against lefties, and has done well in the past versus Moyer, with five hits -- including a double and a home run -- in 12 at-bats.
• Jeremy Hermida, OF, Marlins: After amassing 95 walks to 243 strikeouts the past two seasons, Hermida has seven walks to eight strikeouts so far this season, numbers more in line with his minor league track record. He faces Pirates righty Ross Ohlendorf, who just gets bombed by left-handers: a .359 batting average against and eight home runs in 38 2/3 innings.
• Scott Hairston, OF, Padres: Hairston launched a home run off of Cole Hamels on Saturday, giving him 20 career homers in 364 at-bats against left-handed pitchers. That projects to 30 home runs over a full season, making Hairston a gold mine in deep leagues as long as you can spot-start him against southpaws.
Injury list: Out
• Cristian Guzman, SS, Nationals (15-day DL, hamstring)
• Daisuke Matsuzaka, SP, Red Sox (15-day DL, shoulder)
• Melvin Mora, 3B, Orioles (15-day DL, hamstring)
• Xavier Nady, OF, Yankees (15-day DL, elbow)
Injury list: Day-to-day
• Ronnie Belliard, 2B, Nationals (back; available to pinch-hit)
• Jay Bruce, OF, Reds (hand)
• Eric Chavez, 3B, Athletics (shoulder)
• Stephen Drew, SS, Diamondbacks (hamstring)
• Yunel Escobar, SS, Braves (abdominal)
• Nomar Garciaparra, SS, Athletics (calf)
• Chipper Jones, 3B, Braves (thumb)
• Jeff Keppinger, SS, Astros (back)
• Hideki Matsui, OF, Yankees (knee; available to pinch-hit)
• Kazuo Matsui, 2B, Astros (back)
• Jack Wilson, SS, Pirates (thumb)
• Two weatherproof games for Monday: Reds-Astros and Rockies-Diamondbacks.
• Rain is going to be a threat for most of the East Coast, with Washington facing a 40 percent chance of thunderstorms and Pittsburgh, New York and Philadelphia all with a whopping 70 percent chance of rain. The rain isn't scheduled to let up much, either, so don't be surprised to see a few postponements.
Adam Madison is a fantasy baseball analyst for ESPN.com.