Oswalt, Happ both to start on Friday

So, you think it's tough to rank pitchers for a single start? The thankless task is even more difficult as the trade deadline approaches. Consider the following: J.A. Happ is 3-0 with a 1.53 ERA against the Washington Nationals. Not bad, right? Well, against the Milwaukee Brewers, he has a not-so-impressive ERA of 6.14. Now add to the mix the fact that the Philadelphia Phillies have scored 114 more runs than the Houston Astros this season. Now that he and Roy Oswalt have switched teams, you now know Oswalt is not only the better pitcher, but also has the better matchup, assuming both pitch on Friday and aren't sitting on planes.

For starters

Starting pitcher rankings for July 30

Rk.: The author's ranking of that pitcher for that day only. T: Pitcher throws left-handed or right-handed. Opp: The pitcher's opponent for the day. Rating: The starting pitcher's matchup rating -- separate from the author's ranking -- which accounts for past history (three years' worth as well as past 21 days), opponent and ballpark. Ratings range from 1-10, with 10 representing the best possible matchup, statistically speaking, and 1 representing the worst. W-L: Pitcher's win-loss record. ERA: Pitcher's earned run average. WHIP: Pitcher's average number of walks plus hits surrendered per inning.

Selected notes:

At the top: Can we flip a three-sided coin? Jon Lester goes up against the wounded Detroit Tigers, which as a team is hitting just .241 during the past two weeks. Chris Carpenter faces the Pittsburgh Pirates, who have tagged him with a loss just once in a dozen decisions. Meanwhile, Tim Lincecum is 4-1 lifetime against the Los Angeles Dodgers with a 3.54 ERA. All will be solid plays.

Shaun Marcum has never defeated the Cleveland Indians, and even lost to them earlier this season, allowing five runs in just four innings. However, he does have a 2.52 ERA at home and is a pretty good candidate for reaching double-digit wins. He's certainly facing a weaker overall lineup than Ervin Santana, who owns a 5.77 career ERA against the Texas Rangers.

Johnny Cueto has a 2.08 ERA against the Atlanta Braves and hasn't allowed more than two runs in a game since June 12. Phil Hughes on the road is a much better pitcher than Phil Hughes at Yankee Stadium. Away from the Bronx, he's 5-1 with a 2.36 ERA this season.

Key return: Brett Anderson is expected to be activated from the disabled list for a start against the Chicago White Sox, but after two bouts with elbow tendinitis, it's wise to be a little cautious here.

Streamers on alert: Ian Kennedy did defeat the New York Mets just 10 days ago, albeit with the minimum effort allowed for a starter to do so -- one earned run in five innings pitched. Justin Masterson is 2-0 with a 2.04 ERA against the Toronto Blue Jays. You might want to gamble on Jeff Karstens, as one of his two wins this season came in May against the St. Louis Cardinals via six shutout innings.

Stay away: Manny Parra not only has an ERA of 5.18 against the Houston Astros, but he allowed four runs in five-plus innings against them last month. Expect the same old story here. Scott Feldman is 4-6 with a 5.50 ERA lifetime against the Los Angeles Angels. No matter the uniform, it's hard to get behind Sean O'Sullivan and his 9.31 ERA against the Baltimore Orioles.

Hitter matchup ratings for July 30

Hitter ratings account for the opposing starting pitcher's past history (three years' worth as well as past 21 days) as well as ballpark factors. "LHB" and "RHB" ratings account only for left- and right-handed batters, respectively.

Hitters' count:

Placido Polanco, 3B, Phillies: Polanco's return to the lineup has been a welcome one for the hurting Phillies, as he's hit .309 since the break. Next up is Craig Stammen, against whom the third baseman is 4-for-5 in his career.

Garrett Jones, 1B, Pirates: Jones is on a roll, having just hit a pair of homers against the Rockies on Wednesday, and he has done well in the past -- an .857 slugging percentage -- against Chris Carpenter.

Skip Schumaker, 2B, Cardinals: Amid a 6-for-13 stretch in which he's been playing every other day, Schumaker should have an "on" day on Friday.

Jose Guillen, DH, Royals: He's seen several teammates move recently, and should be playing for his golden ticket elsewhere. Plus, Guillen is batting .377 against the current Orioles' staff.

Adam Jones, OF, Orioles: Jones has done a solid job of maintaining his level of play this month, and now it's time for him to take it to the next level. With a .600 batting average against Sean O'Sullivan, this is a nice place for him to start.

Pitchers' count:

Rafael Furcal, SS, Dodgers: Cold spells are part of the game, but after going 1-for-19, it's hard to expect the ice to melt against Tim Lincecum, against whom Furcal is hitting just .188.

Prince Fielder, 1B, Brewers: If the goal is to stay in Milwaukee, batting .182 since June 21 may seal that deal. It's probably best to steer clear of Mr. Fielder until the trade dust settles.

Kelly Shoppach, C, Rays: He may know how to call a no-hitter, but he's no hitter. Batting just .118 with no extra-base hits in July, the catcher has a .216 lifetime average against the Yankees' current arsenal of arms.

Josh Hamilton, OF, Rangers: Sit out a guy hitting .407 for the month? That's up to you, but Hamilton's July doesn't make his 2-for-18 career record against Ervin Santana any prettier.

Austin Jackson, OF, Tigers: Jackson is batting just .111 against the current Red Sox pitching staff, and may well sit out again on Friday if the Tigers are showcasing Ryan Raburn in the hopes of a deadline deal.

Baseball Challenge Pick of the Day

Carlos Lee, LF, Astros: I had Lee slotted here before his two-homer explosion on Wednesday, based on his 9-for-17 career success against Manny Parra. Seeing the ball start to fly off his bat again, if only for one day, makes me even more confident.


Injury list: Out

Ian Kinsler, 2B, Rangers 15-day DL, leg)

Joel Pineiro, P, Angels (15-day DL, strained oblique)

Shane Victorino, OF, Phillies (15-day DL, left abdominal strain)

Ryan Rowland-Smith, P, Mariners (15-day DL, lower back)

Jamie Moyer, P, Phillies (15-day DL, left elbow)

Chris Coghlan, OF, Marlins (15-day DL, left knee)

Rod Barajas, C, Mets (15-day DL, strained left oblique)

Orlando Hudson, 2B, Twins (15-day DL, strained right oblique)

J.D. Martin, P, Nationals (15-day DL, lower back)

Eugenio Velez, OF, Giants (15-day DL, head injury)

Carlos Guillen, 2B, Tigers (15-day DL, strained right calf)

Magglio Ordonez, OF, Tigers (15-day DL, fractured ankle)

Ben Sheets, P, Athletics (15-day DL, strained right elbow)

Injury list: Day-to-day

Andrew Bailey, P, Athletics (back)

B.J. Upton, OF, Rays (sprained ankle)

Jimmy Rollins, SS, Phillies (foot)

J.D. Drew, OF, Red Sox (hamstring)

Nick Punto, 3B, Twins (hamstring)

Jason Bay, OF, Mets (concussion)

Justin Upton, OF, Diamondbacks (hip)

Weather concerns

Weatherproof games: Indians at Blue Jays, Yankees at Rays and Brewers at Astros: The coasts should be safe from the wet weather on Friday, but there's always rain somewhere it seems, and for this day, the unlucky cities are St. Louis and Minneapolis.

AJ Mass is a fantasy baseball, football and college basketball analyst for ESPN.com. You can follow AJ on Twitter or e-mail him here.