BLACKMON PACES A TOP-HEAVY ROCKIES LINEUP

Penciling in Charlie Blackmon atop the Rockies lineup nearly every day is more than a convenience. He is their best hitter. Giving him the most at-bats is a wise side note.

If only Colorado’s hitters filled in so well behind him. Blackmon’s solo home run in the sixth inning Wednesday — a 424-foot blast over the center field wall — was his 32nd, the most in baseball among lead-off hitters. But it was half of the Rockies’ run total in a 6-2 loss to Detroit.

Blackmon has one month to chase a record held by the Yan- kees’ Alfonso Soriano, who hit 39 home runs from the leadoff spot in 2006, the most ever. (Baltimore’s Brady Anderson hit 50 homers in 1996, but only 15 came when he hit leadoff ).

The Rockies have Blackmon’s name in concrete atop the order. His career-high 84 RBIs are tied with Taylor Douthit, who did it for St. Louis in 1930, for secondmost in the National League in a season. Craig Biggio had 88 for Houston in 1998.

If he looks unlike a traditional leadoff hitter — at 6-foot-3, 210 pounds he has just 13 stolen bases — it only understates his value. Blackmon leads the Rockies in at-bats and plate appearances and his 1.023 OPS (on-base plus slugging percentage) is fifth-best in baseball, behind only Miami’s Giancarlo Stanton, Cincinnati’s Joey Votto, Washington’s Bryce Harper and Arizona’s Paul Goldschmidt.

But there’s a problem.

After the top three hitters, the rest of the Rockies lineup continues to struggle against Detroit. Their 5 through 9 hitters combined to go 3-for-18 on Wednesday.

Backup catcher Tony Wolters singled in the eight inning, with the game already out of hand, to snap an 0-for-22 hitless skid.

More rotation questions.

Rookie Antonio Senzatela is scheduled to pitch Sunday at Coors Field against the Diamondbacks to finish a critical weekend series. But Senzatela in his last outing gave up four runs on six hits in just 3M innings in a loss to the Tigers on Monday. That may leave his rotation spot in doubt.

“I can probably answer that in a couple of days,” Colorado manager Bud Black said. “We’re talking about a lot of things.”

If the Rockies choose a different route, there is no clear substitute. Rookie right-hander Jeff Hoffman remains in Triple-A Albuquerque after giving up six runs in less than one inning last week. He is scheduled to pitch for the Isotopes on Sunday. Lefty Tyler Anderson is also in Triple-A rehabbing a left knee injury. He will pitch Thursday.