CHICAGO -- Cubs third baseman Aramis Ramirez will test his left thumb this weekend, playing with Class A Peoria on Saturday and Sunday, and could be back in the lineup next week.

He's been on the disabled list since June 8 because of a sprained left thumb and has taken batting practice every day this week.

"It feels better, but until I play the game ... you know, [batting practice] is one thing, in a game is another," Ramirez said Friday. "We'll see how it is after I play."

If Ramirez is able to return next week, he could be used as a designated hitter. The Cubs will play six consecutive Interleague games in American League ballparks, starting Tuesday with three games in Seattle.

Playing third hasn't been the issue, Ramirez said, although the swelling in his hand was aggravated when he wore a glove.

"I'm fine to play third base," Ramirez said. "Swinging is the key, that's going to be the key. That's why I'm going to test it Saturday and Sunday."

"We have an opportunity to DH him, play him at third or a combination of both," Cubs manager Lou Piniella said. "The other guys have been playing, the weather's getting hot. We need to rest them, too."

Looking ahead to the games against the Mariners and at U.S. Cellular Field against the White Sox, the Cubs could start Xavier Nady at first and have Derrek Lee be the designated hitter, or start Tyler Colvin in center or left and use Marlon Byrd or Alfonso Soriano as the designated hitter.

"That's Lou's decision," Ramirez said. "If he wants me to DH, I'll DH. If he wants me to play third, I'll play third. It doesn't really matter."

Ramirez was expected to get six to eight at-bats over the weekend with Peoria. He has been working with hitting coach Rudy Jaramillo and adjusted his grip slightly.

"I've been hitting the same way for 15 years," Ramirez said. "[I changed] just a little bit."

"If he's fine, we'll get him back on the [active] list, and hopefully he's nice and productive for us," Piniella said.

Ramirez was batting .168 with five home runs and 22 RBIs in 47 games.

"I've just got to get healthy and try to help this team," Ramirez said.

Colvin leads off against Angels' Kazmir

CHICAGO -- The Cubs had a new leadoff man Friday as manager Lou Piniella inserted rookie Tyler Colvin into the top spot in the order against Angels lefty Scott Kazmir.

Colvin went 2-for-4, including a three-run homer in the ninth, and scored another run in the Cubs' 7-6 loss to the Angels. He tried to downplay the move.

"You only have to lead off once -- that's what they say," Colvin said.

"He looks like an exciting young player," Angels manager Mike Scioscia said. "I don't know exactly where he's going to be used in the lineup. He hangs in against lefties well and hit that cutter [off Francisco Rodriguez] way out."

Colvin replaced Ryan Theriot, who has led off against lefties this year. But Theriot entered Friday averaging 3.56 pitches per plate appearance, had a .312 on-base percentage, and was batting .247 against left-handers. Colvin's PPA wasn't much better -- 3.71 -- and he was hitting .250 against lefties, but so far this season, southpaw hitters were batting .420 off Kazmir.

"Left-handers have hit Kazmir here early in the year," Piniella said. "I've been using Colvin to pinch-hit against left-handers anyway. Get him out there and let him play."

The only other option for the leadoff man, Piniella said, is rookie shortstop Starlin Castro, but he entered Friday batting .196 in June after hitting .310 in May.

"The amazing thing about Castro is when you look at his batting average, there's a 100-point difference when he hits in the bottom of the lineup as opposed to the top," said Piniella of Castro, who is batting .238 in the No. 2 spot and .308 in the eighth spot. "Could I hit him second? Yes. [Jeff] Baker's been swinging really good against lefties and we get his bat at the top of the lineup. If we had to hit Castro up there, we could."

Being at the bottom of the order may help Theriot, too.

"Let him see some pitches," Piniella said. "Sometimes it helps you relax a little bit, too."

Colvin, who has primarily batted fifth or sixth with the Cubs, didn't know about the lineup switch until he was walking into the players' lounge for a pregame hitting meeting. He did not bat leadoff in high school, college or the Minors.

"I'll help out any way I can," Colvin said. "If [Piniella] wants me to lead off, I'll lead off."

Byrd, others have Piniella's All-Star vote

CHICAGO -- In-stadium All-Star balloting ended this week at Wrigley Field, but fans can still vote for their favorite Cubs players online. Maybe a surge will get Marlon Byrd onto the National League team.

Byrd ranks third among all NL hitters with a .328 average, is third in hits (80), and second in multi-hit games (27).

He's also been stellar in center field, making diving catches on a regular basis.

"He gets a good jump on the ball, he's got good hands," manager Lou Piniella said of the center fielder. "He positions himself well. He has a very respectable throwing arm. With the bat, he's been leading our team in hitting the whole year. ... He gives us energy. He's a good, solid Major League player."

So far, Alfonso Soriano is the only Cubs player listed in the latest All-Star balloting, ranked 11th among outfielders. Piniella would like to see Byrd make the team.

"It would be wonderful," Piniella said. "He would be the young man from our team who obviously deserves a big shot at that. We've got the closer [Carlos] Marmol and how about [Carlos] Silva? We'll see what happens with it. we have a few people who deserve to be at the All-Star Game."

You can vote for starters up to 25 times at MLB.com and all 30 club sites using the 2010 All-Star Game MLB.com Ballot sponsored by Sprint until July 1 at 10:59 p.m. CT. Sprint subscribers can now vote on the go with select Sprint devices. They can learn more about how to vote on their smart phones at MLB.com/Sprint.

The All-Star Game will be played July 13 in Anaheim.