Hector Santiago's 2015 began as an All-Star and an early-season Cy Young contender. Over the last two months, he's more often been a hindrance.

If he can't get it together Tuesday night in Houston, the Los Angeles Angels figure to fall farther behind the wild card-leading Astros while squandering what's likely their most important remaining series.

The Astros (80-71) won 6-3 Monday in the first of the three-game series, extending their lead for the second wild card to 3 1/2 games over the Angels (76-74) and three over idle Minnesota. Texas was also off so the Astros' three-game winning streak has them within a game of the AL West lead following a five-game skid.

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Another win would put to rest a painful streak of six straight losing seasons, though their goals are set a little higher than that. Offensively, they've come around with 5.2 runs per game a .280 average over their last 25 games, and their .247 season average is tied for their high-water mark.

Los Angeles, which completes a span of 10 of 13 games coming against Houston and Minnesota on Wednesday, has still won five of eight against those key teams though Monday's defeat was its sixth straight at Minute Maid Park. The Angels need more from Albert Pujols, who's batting .146 over his last 22 games and .157 at Houston in 22 games since the start of 2013.

Santiago (8-9, 3.47 ERA) is coming off his worst start of the season, though it resulted in Thursday's 11-8 win in Minnesota. The left-hander gave up five runs and five hits in 2-3 of an inning and is 1-5 with a 5.98 ERA in his last 11 starts.

"It just piled on," said Santiago, who went 7-4 with a 2.30 ERA in his first 18 starts. "I fell behind in some counts and I wasn't right on."

The shift has probably had more to do with control than anything. Through that span of success that extended into his first start after the All-Star break, Santiago issued 2.78 walks per nine innings with a .286 opponent on-base percentage. Since, those numbers are up to 4.78 and .343.

He's given up five earned runs in his last three road starts and is 0-4 with a 9.00 ERA in six away outings since the All-Star break, though he has dominated the Astros this year with a 1.40 ERA and .123 opponent batting average in three starts without a decision.

Jed Lowrie (0 for 15), Colby Rasmus (0 for 6), Luis Valbuena (0 for 5) and George Springer (1 for 8) have highlighted those struggles.

The Astros counter with Lance McCullers, who hasn't had an offense bailing him out like Santiago's last start. Houston has dropped his last four starts, though McCullers (5-6, 3.18) is 0-2 with a 3.38 ERA, .213 opponent batting average and 1.50 run-support average in them.

The right-hander gave up three runs and five hits in six innings of an 8-2 loss in Texas on Thursday. If there's any knock on the 21-year-old's recent form, it's that he's walked 4.13 batters per nine innings after entering that span with a 3.01 mark.

"I feel like I put my best foot forward," McCullers said. "I feel like I threw the ball pretty well, some jams I wish I would have been able to avoid, especially early."

The rookie is 1-0 with a 2.00 ERA in three starts against the Angels.