Updated

It's almost certain that the Texas Rangers are going to reach the postseason. But, nailing down that spot hasn't been so easy.

On Saturday, the Rangers hope to secure their third straight playoff appearance when they play the middle test of a three-game series against the surging Los Angeles Angels of Anaheim at Rangers Ballpark in Arlington.

In Friday's opener, Jered Weaver spun seven strong innings to become the AL's first 20-game winner and kept Los Angeles in the thick of the playoff race with a 7-4 victory over the AL West-leading Texas Rangers.

Weaver (20-4) scattered five hits and walked two while striking out five to earn the victory in the opener of this three-game set. The right-hander is the seventh Angel to win 20 games and the first since 2005 Cy Young winner Bartolo Colon.

"It's a great accomplishment," Weaver said of his career-high 20th win. "I didn't think that I'd ever do it. I have to thank my teammates for getting me to where I'm at. It's a great personal accomplishment but I'm all for winning a World Series before any of that stuff."

Mark Trumbo registered three hits and three RBI, while Mike Trout added a solo homer for the Halos, who have won six of seven and sit two games back of Oakland for the final wild card spot after the A's downed Seattle on Friday.

Ryan Dempster (7-3) was pegged with the loss after giving up four runs on seven hits and four walks. He struck out seven over 5 2/3 frames.

Adrian Beltre clubbed a two-run home run and Nelson Cruz smacked a solo homer for Texas, which has lost three of four and missed out on a chance to clinch a playoff berth with a victory.

"We're not taking anything for granted," outfielder David Murphy said. "We're going to come out playing hard, keep fighting and keep racking up wins."

The Rangers still hold a three-game lead on the A's in the division, but can clinch at least a wild card spot with a win on Saturday.

Getting the call for the Angels on Saturday will be righty Ervin Santana, who is 9-12 with a 4.93 ERA. Santana was terrific in beating the Chicago White Sox his last time out back on Sept. 21 when he allowed a run and two hits and struck out 11 in seven innings.

Santana, who can become a free agent at season's end, has pitched to a 2.88 ERA since the start of August, but has served up a major league-high 36 home runs on the season.

"I don't have to prove anything," Santana said. "I just have to believe in myself, trust my stuff and pitch."

Santana beat the Rangers the last time he faced them and is 13-10 with a 5.81 ERA in 26 games.

Texas will hand the ball to lefty Derek Holland, who has won his last four decisions and is 11-6 with a 4.50 ERA. Holland only lasted three innings on Monday against Oakland, though, as he surrendered three runs and four hits with two walks. However, he did not factor in the decision of his team's 5-4 win.

"I didn't do my part," Holland said. "I was very disappointed with the way I pitched, but the bullpen came up huge tonight. I was behind every batter and wasn't throwing anything for strikes. I was very erratic."

Holland is 6-5 lifetime versus the Halos with a 5.27 ERA in 15 games (12 starts).

The Angels have won nine of 17 meetings this season, but Texas has won four of its last six in the series.