DENVER -- Don't even mention a sophomore jinx to Tyler Colvin. He doesn't believe in such things.

"[On Friday], I felt great at the plate and had nothing to show for it," said the Cubs outfielder, who is batting .135. "I'm working with [hitting coach Rudy Jaramillo] every day. It's just getting them to fall where they aren't."

In Houston on Tuesday, Colvin was 2-for-4 with his second home run. He felt good then, too.

"I just have to go up there and keep battling and know it'll turn around," said Colvin, who batted .254 last season, his first in the big leagues. "It definitely can't get any worse. It's not hurting my morale any -- I know I can hit. I'm just starting slower than I'd like."

Cubs manager Mike Quade said Colvin may be pressing.

"His discipline hasn't been as good, and often times that happens when you start pressing," Quade said. "It's human nature to struggle some, and instead of being more patient you wind up being more aggressive and fighting to get out of it. ... He'll be fine, but he has to be disciplined and get pitches to hit, and when he does that, he's so talented, he'll be fine."

Colvin has tweaked his swing and dropped a leg kick that he had been using as a timing mechanism. He's felt better since losing that.

And that sophomore jinx?

"I don't believe in that stuff," Colvin said. "Either I can hit or I can't, and I know I can hit, and I will."

Russell to start Tuesday's game vs. Padres

DENVER -- James Russell will get a second start on Tuesday when the Cubs face the Padres, but the lefty still could pitch Sunday in relief if needed.

Before Saturday's game, Cubs manager Mike Quade said it would be either Russell or Jeff Samardzija on Tuesday. Russell got one out in the Cubs' 8-3 win over the Rockies, facing pinch-hitter Todd Helton. Samardzija threw in the bullpen.

"It was a flip of the coin, really," Quade said about the decision. "I decided we'd let [Russell] start and think about a tandem again. The more I talk about the fact that we're asking a couple bullpen guys to give us innings and start for us, the more I think they're bullpen guys. If something arises where we need one of those guys to get us outs to win a game here, and probably [Sunday] would be the last day, then we'll do it."

The Cubs have decided to stay in-house rather than dip into the Minor Leagues to fill Andrew Cashner's spot while he rehabs from a strained right rotator cuff.

Quade compared the Padres' numbers against left-handers and right-handers to see if the Cubs would benefit somehow, but said it was a wash.

Russell started last Tuesday in Houston and was followed by Samardzija. No matter who got the call, it's a temporary thing.

"I believe that [Samardzija] and 'Russ' are both bullpen guys who happen to be in the mix for starting on Tuesday," Quade said. "I believe that in my heart of hearts. I want them to stay in that mindset right now, and I don't want anything to change except instead of me handing you the ball in the fifth inning to get four, six outs, I'm handing it to you in the first inning to get the outs that you can. The same is true no matter who goes out there."

They just happen to be relievers who are starting. They also happen to be very much in step. As Quade was talking to the media before Saturday's game, Russell and Samardzija came in from the outfield together, stride for stride.

Fukudome returns to Cubs' lineup

DENVER -- Kosuke Fukudome, who has missed four games because of a strained left hamstring, was back in the Cubs' lineup Saturday.

"The main thing I wanted him to do is walk in and I say, 'Are you ready to go?' and he said, 'I'm ready,'" Cubs manager Mike Quade said Saturday.

Quade said that if he senses that Fukudome isn't 100 percent, he will pull him from the game. The right fielder was inserted into the seventh spot in the lineup, not leadoff partly because Quade didn't want him running and mainly because the manager likes his one-two combination of Starlin Castro and Darwin Barney.

"Right now, I'm going to leave those guys there," Quade said.

Fukudome was injured last Sunday making a running catch in the fifth inning at Miller Park in Milwaukee. He took batting practice on Friday and did run.

The outfielder was batting .313 before he was injured. Tyler Colvin, who started in right field while Fukudome was out, was batting .135.