ST. LOUIS -- Xavier Nady's elbow has passed all the tests and he's looking forward to having an offseason to strengthen it -- not focus on rehab.

He's also curious as to where he'll be next year.

Nady took over first base for the Cubs when Derrek Lee was traded to the Braves on Aug. 18. Nady entered Wednesday's finale with the Cardinals batting .338 (27-for-80) since Aug. 20.

"Overall, it's been a wild year," Nady said.

He wasn't sure what to expect coming off a second Tommy John surgery on his right elbow. Playing first has been easier on him than the outfield because the throws are shorter. But Nady, 31, signed a one-year deal with the Cubs. If he goes, the team doesn't have a first baseman in waiting.

"I love it here," Nady said. "It's a wonderful organization, unbelievable city, fans. The year hasn't gone as planned and it's been frustrating from a team standpoint, and a lot of guys know we're better than this."

There's also the question of who will be the manager. That's something else to be determined this offseason. Does it matter to Nady?

"Not really," he said. "I haven't put much thought into anything, to tell you the truth. I've been happy to be somewhat healthy and play on a regular basis."

Colvin joins annals of history with 20th homer

ST. LOUIS -- Cubs outfielder Tyler Colvin became the fourth rookie in franchise history to hit 20 home runs in a season when he connected on a three-run shot in the seventh inning of Wednesday's 7-3 victory.

Colvin homered off St. Louis' Chris Carpenter, hitting a 3-2 breaking ball into the right-field seats.

"I felt like I threw the ball well," Carpenter said. "Colvin, I made a good pitch, the pitch I wanted to make."

The rookie got lucky.

"That's what I was guessing," Colvin said of Carpenter's selection. "That's probably his best pitch right there."

"There are times when you get a break against a very good pitcher, and he got a pitch to hit," said Cubs manager Mike Quade.

It was Colvin's first homer since Aug. 24.

"I pay attention to individual milestones to an extent," Quade said, "and he was sitting on 19 for a while and you hope he gets to 20 -- you'd like him get to 40 -- but that was a great thing."

The rookie joins Hall of Famer Billy Williams (25 homers in 1961), Geovany Soto (23 in 2008) and Walt Moryn (23 in 1956) in the Cubs' record books. Williams and Soto both won National League Rookie of the Year honors in their first full seasons.

Colvin now is tied with Florida's Mike Stanton for the home run lead among rookies. The two square off this weekend when the Cubs travel to Miami for a three-game set.

Colvin didn't set 20 as a goal.

"I never really set any statistical goals like that," Colvin said.

Barney admirably filling in for injured Castro

ST. LOUIS -- Cubs shortstop Starlin Castro did not start for the third consecutive game Wednesday to give his left hip time to heal, but substitute Darwin Barney has made it easy to keep Castro on the bench.

Barney was batting .406 with eight runs scored, two doubles and two RBIs in his past 11 games entering the finale with the Cardinals, and he collected his first Major League three-hit game on Tuesday.

"Barney's playing well and I don't think 'Cassie' is 100 percent yet," said Cubs manager Mike Quade. "We have the luxury of a guy playing well. Let's give [Castro] another day with the off-day and get him back to 100 percent when we get to Florida. I'd be shocked if he wasn't ready to go on Friday."

Castro has been nursing a bruised left hip, injured a week ago in a collision at first base with the Astros' Brett Wallace. Castro played in the weekend series against the Brewers, but he was visibly limping.

Barney batted .297 in 113 games for Triple-A Iowa this season and primarily played shortstop.

"I think he'll be a real nice Major League player," Quade said. "Whether he's an everyday player or a versatile guy, that I don't know. His bat will probably determine that because all the intangibles, the defense and the other stuff you're looking for, he does well. He's a very interesting kid."

Barney surprised Quade when he subbed at third base for the Cubs, making some heads-up plays despite not being that familiar with the position.

"When you see a guy with those kind of instincts, you feel good about putting him out there defensively anywhere," Quade said.

Cubs may adjust rotation for final homestand

ST. LOUIS -- The Cubs have their rotation set for the weekend series against the Marlins, but the may make some adjustments for the final homestand, which begins Tuesday against the Giants.

Tom Gorzelanny (7-8, 3.90 ERA), who has not pitched since Sept. 1 after taking a line drive off his left hand, will throw a five-inning simulated game Friday and could be inserted into the rotation Sept. 22.

However, Randy Wells (7-13, 4.46 ERA) may start that day and Gorzelanny could get an extra day on the side. It all depends on whether the lefty needs more time.

Manager Mike Quade is looking ahead to the upcoming series against the Giants and Padres, whom the Cubs play from Sept. 27-30.

"You want to put the best club out there against contenders," Quade said. "If there's a distinct matchup, maybe we'll lean that way."