Westward ho! Cardinals embark on their toughest trip yet

ST. LOUIS -- For tourists, an 11-day trip to Colorado, Los Angeles and San Francisco would be delightful this time of year. For the Cardinals, however, their trip that begins Monday night at Coors Field looms as the toughest of the season.

"We've had some tough trips but yeah, Colorado's always a tough assignment, LA obviously is a good club, and we've already seen San Francisco and know that they're a good team as well," manager Mike Matheny said Sunday.

And that was before starters Michael Wacha and Jaime Garcia and second baseman Kolten Wong landed on the disabled list.

All things considered, the Cardinals should be happy to go 5-5 on their first journey west of Kansas City this season. Here are three reasons the trip will be so challenging:

THE ROTATION IS HURTING

Though the Cardinals have more depth than most teams to cover for three disabled starters, they still have to fill at least two turns with someone from the Tyler Lyons ilk. The first turn will come Wednesday at Colorado, which is hardly a spot you want to bring up an untested starter. Lyons, by the way, is healthy but was hit hard in his first start back in Class AAA last week.

Just as important as finding someone for the fifth spot, the Cardinals need Carlos Martinez and Shelby Miller to grow up quickly. They will combine for four starts on the trip and the Cardinals can't afford for more than one of them to be a clunker. Unfortunately for Miller, one of his starts comes at Coors Field, the most hitter-friendly park in the majors and a place where he will be pitching for the first time Tuesday night.

At least Adam Wainwright showed no ill effects of his mini bout with tendinitis and Lance Lynn is on one of his better rolls. Lynn could give the Cardinals a huge lift with a strong outing Monday night at Coors Field, where he has pitched well. Lynn has started twice at Coors Field and allowed only two runs in each.

Best-case scenario, Joe Kelly (hamstring) will be ready to rejoin the rotation on the next homestand. He is scheduled to make his first rehab start Friday for Memphis. Because he has been able to keep his arm strength up in his long stay on the DL, Kelly is expected to throw up to 60 pitches. If all goes well, he could need only one other rehab assignment.

THE BULLPEN WILL BE LACKING

Manager Mike Matheny joked Sunday that he wished he could take 20 relievers to Colorado. You can understand why when you see what the Rockies are hitting at home: .329/.377/.533. They're averaging 6.4 runs a game, more than a run per game more than what any other team is scoring at home and nearly 2 1/2 better than what the Cardinals have scored at Busch Stadium (4.0).

Instead, the Cardinals will return to a 12-man pitching staff after they called up only one reliever, Eric Fornataro, and a shortstop, Pete Kozma, to take the roster spots of Wacha and Garcia.

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The bullpen already has received welcomed and at least mildly surprising boosts from lefties Sam Freeman and Nick Greenwood. Now they will need Fornataro to step up and the relievers after Trevor Rosenthal and Pat Neshek to pick it up.

Seth Maness figures to be particularly important at Coors Field, where keeping the ball down is more important than swing-and-miss stuff. Jason Motte remains somewhat of an unknown as he continues to come back from Tommy John surgery. Motte has gotten his fastball up to 95 mph in his past three outings but he still isn't being used that much and hasn't developed much of a role yet. Look for that to change on this trip.

THE OPPOSITION IS TOUGH

Yes, the Rockies hit like crazy at home, the Dodgers have been playing better and the first-place Giants already bullied the Cardinals around at Busch Stadium three weeks ago.

But like the Cardinals, none of their upcoming opponents is without issues. While the Rockies score a lot at Coors Field, they also give up a lot. Their 5.11 home ERA is the worst in the majors. The Rockies also enter this series on a six-game losing streak, including a weekend sweep by the Brewers in Denver.

The Cardinals will see both Clayton Kershaw and Zack Greinke at Dodger Stadium, as well as Hyun-jin Ryu and Josh Beckett. But for all their pitching, the Dodgers are two games under .500 at Dodger Stadium because they have more trouble scoring at home than the Cardinals have had at Busch Stadium.

As strong as the Giants looked in St. Louis, the Cardinals have a better record since the teams last met. Dealing with issues at the back of the bullpen, San Francisco has lost nine of its past 12 games. The Cardinals have gone 11-8.

"I can't wait to get back out there," Matheny said about a rematch with the Giants. "We have a different team to show them than we showed them the first time."

Different in a better way, he meant. But different also could mean lacking after the weekend injury reports.

You can follow Stan McNeal on Twitter at @StanMcNeal or email him at stanmcneal@gmail.com.