WHAT TO WATCH FOR

The Angels are 50-42 and 11/2 games behind the Texas Rangers in the American League West as they resume play Friday at Oakland. How the season’s second half shapes up:

Top story lines

It might rate a notch below Philadelphia’s Roy Halladay and Cliff Lee, but the one-two pitching punch of Jered Weaver and Dan Haren has been one of baseball’s best. Weaver is 11-4 with a major league-best 1.86 earned-run average, 120 strikeouts (sixth in the AL) and a .194 opponents’ batting average (third). Haren is 10-5 with a 2.61 ERA, and his 5.75-to-1 strikeout-to-walk ratio is the best in the AL. Center fielder Peter Bourjos, in his first full big league season, has been spectacular on defense, saving more runs than any other player in baseball. Rookie closer Jordan Walden, armed with a 99-mph fastball, blossomed after being thrust into the closer role in early April. He has a 2.84 ERA and 20 saves in 39 games. Rookie first baseman Mark Trumbo has eased the loss of Kendrys Morales with a team-leading 17 homers and 41 runs batted in.

Players to watch

Torii Hunter has been slowed by nagging injuries and a reluctance to embrace a switch to the No. 2 spot in the batting order. His batting average hovered around .230 for most of the first half, and he grounded into 19 double plays, second-most in the AL. But as June turned to July, Hunter rallied. He hit .361 (22 for 61) with three homers and 11 RBIs in 18 games before the break, raising his average from .225 to .250. Middle-of-the-order veterans Bobby Abreu and Vernon Wells also are keys. Abreu has been consistent all season, with a .277 average, .394 on-base percentage, 35 RBIs and a team-high 59 walks. After a frigid start, Wells has nine homers and 21 RBIs in his last 25 games.

On the farm

Kevin Jepsen is the one player in the system who could make a difference in the second half, but the right-hander must regain the form that made him the team’s primary setup man in 2009. Jepsen had a 6.75 ERA when he was demoted to triple A on April 10. He was recalled May 11 but was so erratic that in early June he was sent back to Salt Lake, where he is 1-2 with a 3.90 ERA in 23 games.

Buyer or seller?

Buyer with limited options. Wells and Hunter are entrenched in the corner outfield spots, as is Abreu at designated hitter, and the Angels love Bourjos’ defense in center. Trumbo is a budding star, Howie Kendrick is an All-Star at second base, Erick Aybar is a superb shortstop and catcher Jeff Mathis, for all his shortcomings as a hitter, is far better defensively than Hank Conger. That leaves third base, where Alberto Callaspo (.281) is having a decent season, as the logical spot for a lineup upgrade. Among possible targets are the Chicago Cubs’ Aramis Ramirez, who is hitting .298 with 15 homers and 51 RBIs but has a full no-trade clause, and Baltimore’s Mark Reynolds, who is hitting .227 with a .346 on-base percentage, 20 homers and 49 RBIs. David Wright could soon return from a stress fracture in his back, but the New York Mets don’t seem inclined to trade him. The Angels could also bolster their bullpen, with San Diego closer Heath Bell an attractive target.

Contract drive

Abreu, 37, needs 61 plate appearances for his $9-million option for 2012 to vest. Joel Pineiro’s two-year, $16-million contract expires after this season. He is 5-3 with a 3.90 ERA but has given up 106 hits in 90 innings and has not given the Angels an overwhelming reason to re-sign him.

Last look

Inconsistent and now-injured Fernando Rodney, whose two-year, $11-million deal expires, has been a disappointment and will not return. Well-traveled Russell Branyan will probably be moving on.

Must improve

The Angels need to hit in the clutch. They rank 10th in the AL with a .239 average with runners in scoring position and are last with a .185 mark (10 for 54) with the bases loaded. More consistent middle relief from Hisanori Takahashi and Rich Thompson would also help.

Best-case scenario

The rotation, which has a 3.21 ERA, continues to keep the Angels in games. Rodney recovers from a back injury to bolster the bullpen. The Hunter-Abreu-Wells trio remains productive. Trumbo stays on a 30-homer pace. Kendrick, Aybar and Maicer Izturis provide enough offense to pressure opponents.

Worst-case scenario

An injury to Weaver or Haren dents the rotation. Inconsistent middle relief sinks the bullpen. The offense goes through another dry spell or two like the one in early June, when the Angels -- already shut out more times this season (10) than they were in 2010 (nine) -- scored 15 runs while losing seven of eight.

What’s realistic

The Angels appear good enough to stick with Texas in what should be a two-team race for the AL West title. The teams play each other 13 more times, with 10 of those games in Anaheim.

mike.digiovanna@latimes.com

--

(BEGIN TEXT OF INFOBOX)

Angels 50-42 | 2nd in AL West

Four-season breakdown:

*--* Year 1st half 2nd half Division 2010 47-44 33-38 Third 2009 49-37 48-28 First 2008 57-38 43-24 First 2007 53-35 41-33 First *--*