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09/16/12 9:57 PM ET

Lower back tightness keeps Boggs out of finale

LOS ANGELES -- With Mitchell Boggs unavailable and Edward Mujica questionable, Cardinals manager Mike Matheny didn't have his usual automatic decisions if he needed his bullpen late Sunday to hold a close lead.

Boggs received treatment for lower back tightness on Sunday morning after notifying the staff of the issue after his appearance on Saturday. Boggs said his back tightened when he faced Matt Kemp with two outs in the eighth inning. The right-hander ended up retiring Kemp on a groundout without seeking medical attention.

"I've dealt with it a little bit in the past and as far as that scale, it's the least," said Boggs, who ranks first in the National League with 30 holds. "I was able to continue to pitch. I just got some treatment today and see how it feels."

Boggs has been the Cardinals' go-to reliever in the eighth inning this year. Mujica, the Cardinals' seventh-inning man, was also likely to have to sit on Sunday. While healthy, Mujica has pitched in each of the last three games and in four of the team's last five.

Workload concerns could force Matheny to have to look elsewhere for late-inning help. Closer Jason Motte, who took the loss on Saturday, was available.

Carp to make season debut Friday against Cubs

LOS ANGELES -- Chris Carpenter, whose season was never supposed to get started, has been cleared to return at the most crucial of times. The Cardinals will give Carpenter his first start of 2012 on Friday, when the Cardinals open their final road trip with an afternoon game in Chicago.

Manager Mike Matheny made the announcement on Sunday, one day after Carpenter threw 95 pitches in his fourth simulated game since returning from July thoracic outlet surgery. Once Carpenter reported no unusual soreness the day after the session, the Cardinals felt confident in making the return official.

"I'm looking forward to it," Carpenter said. "We've worked hard to get back and be able to do this. Like we've said all along, we weren't expecting it, but I'm excited. I think it's going to be a lot of fun. I'm looking forward to getting back out there and competing."

Carpenter's season had been declared over in early July, when it was announced that he would be undergoing a procedure to address a nerve-related issue in his neck/shoulder. At the time, it marked the second instance in which Carpenter had been shut down this year. He had to stop throwing in March due to the same problem.

Now, by starting on Friday, Carpenter will be in line to make as many as three starts before the end of the regular season.

"He's a presence on this team," Matheny said. "He's a leader on this team. We're excited for him. We're excited for us. I'm anxious to watch him pitch."

The Cardinals also clarified the rest of their rotation order. Kyle Lohse will stay on turn and pitch Tuesday's series opener against the Astros. Lance Lynn -- not Joe Kelly -- will follow him on Wednesday. Lynn, who made a spot start for an injured Jake Westbrook last Thursday, earned the chance for another with his performance.

Lynn allowed one earned run on five hits and two walks in six innings against the Dodgers. He struck out seven in the 2-1 win.

Taking advantage of the flexibility afforded by Monday's off-day, Jaime Garcia will slot in Thursday. That allows Garcia to pitch at home, where he has a 2.63 ERA this year.

With the pitching set for next week, Kelly is the odd man out, meaning that he will return to the bullpen. Kelly made two August appearances as a reliever before taking Lynn's spot in the rotation when Lynn began to scuffle. In his start on Friday, Kelly surrendered three runs on four hits and two walks in five innings.

Matheny: Cards need to improve on 'little things'

LOS ANGELES -- Though the Cardinals entered Sunday still with a shot at a series split in Los Angeles, a chance to finish the road trip with several more wins was missed largely because of the club's inability to execute fundamentals.

On the defensive side, the club committed six errors in the first six games of the trip. The little mistakes on offense, though, have been even more glaring. An inability to execute a sacrifice bunt has been a recurring issue, and it occurred twice more in Saturday's 4-3 loss.

Situational hitting -- particularly advancing a runner from second with no outs or driving home a runner from third with less than two down -- has been missing, too. No more was that evident than on Wednesday, when the potential tying run reached third with one out and never made it home in the ninth.

Aside from an 11-3 loss in San Diego on Monday, the Cardinals' other four losses on the road trip have come by a combined seven runs. Some of those surely would have turned in St. Louis' favor had fundamentals been better executed, and manager Mike Matheny was not shy in expressing his disappointment in that area on Sunday.

"I think it's a great reminder of no matter how strong an offensive club you are, you have to do the little things," Matheny said. "How many times have we talked this season about missed opportunities and not doing the little things? Yesterday, that was really the most frustrating part of that game -- the little things. Not getting the bunts down, not getting guys over, not making the routine plays.

"I don't care how good an offensive team you have, if you're not doing those things, it's going to bite you."

Matheny has had his club increase its pregame bunting work and incorporate more situational hitting during batting practice.

"It is a hard game, and I understand that," Matheny said. "And sometimes no matter how much work we do, it's a different animal doing it between the lines when the heat is turned out. We're still trying to figure out how to make it happen."

Worth noting

• Carlos Beltran returned to the lineup on Sunday after sitting on Saturday due to lower back tightness. With his first-inning single, Beltran has hit safely in three straight games for the first time since Aug. 9-12.

• The Astros, who open a three-game series at Busch Stadium on Tuesday, will start the following pitchers against the Cardinals: Fernando Abad (0-4, 5.08 ERA), Lucas Harrell (10-9, 3.86 ERA) and Bud Norris (5-12, 4.93 ERA). The Cardinals, who still have six games remaining against Houston this season, lead the season series, 6-3.

• The Cardinals' Double-A affiliate in Springfield captured the Texas League championship with a 2-1 win over Frisco on Saturday. The organization has not captured a sole league championship at the Double-A level since 1989. In 2004, the Cardinals' Double-A club shared the title after weather forced the season to end without a championship series.

Jenifer Langosch is a reporter for MLB.com. Read her blog, By Gosh, It's Langosch, and follow her on Twitter @LangoschMLB. This story was not subject to the approval of Major League Baseball or its clubs.