"I want to make sure nothing is wrong," Guzman said Tuesday.
The right-hander has not pitched since Friday. He felt some tightness on Saturday, but was able to throw on the side Monday in Milwaukee. He woke up Tuesday with the same strange feeling.
"He characterized it as 'tenderness,'" said Cubs assistant general manager Randy Bush. "For his own peace of mind, we want to have him go see the doctor."
Guzman has not received a decision in three starts this season, compiling a 3.52 ERA. In nine relief appearances, he is 0-1 with a 3.60 ERA.
"I don't want to change my release point or arm angle -- I don't want to make it worse," Guzman said.
Was he worried?
"Of course, I'm worried," he said. "My arm, that's why I'm here."
The Cubs are expected to add a right-handed pitcher to fill in for Guzman in the bullpen. One possibility is Sean Gallagher, who is 7-2 with a 3.39 ERA at Double-A Tennessee. In his last start Friday against West Tenn, Gallagher gave up one run on three hits over seven innings and struck out nine. He was 4-0 in five May starts with a 3.34 ERA.
Step by step: There's a reason Alfonso Soriano hasn't been running like crazy on the bases. His left hamstring is a little tender, and he may have aggravated it when he legged out a triple Sunday in Chicago.
"I'm not 100 percent yet," Soriano said Tuesday. "The last three games at home, I haven't felt good."
Soriano is definitely seeing the ball better, notching his third career five-hit game on Monday and hitting his third home run in as many games on Monday as well. He led off Tuesday with a double.
"I've never had a start like I had this year," said Soriano, who has some catching up to do to match his 46-homer season of 2006. "I'm seeing the ball good now."
Good? How about great? In his last four games, Soriano was 11-for-19 (.579) with three homers and five RBIs.
Box seats: Cubs manager Lou Piniella spent Day 3 of his four-game suspension in a suite with Bush and Chuck Wasserstrom, manager of baseball information. Piniella will be back in the dugout on Thursday in Atlanta.
"It looks easy up there," Piniella said. "It looks a lot easier than it does when you're on the field."
Bench coach Alan Trammell was 2-0 as the interim manager heading into Tuesday's game.
"I'm a fan now -- believe me, I'm a fan," Piniella said.
Maybe the Cubs players are more relaxed with Trammell at the helm?
"I disagree with that," Trammell said. "This team is very capable of doing what we've done. We won, 10-1, the other day [vs. Atlanta] and what did I do? We're very capable of playing good baseball. When Lou comes back on Thursday, we'll welcome him."
Helmet cam: Michael Barrett has decided to switch back to the hockey-style catcher's mask he had used until last season and the start of this season.
"I just wanted to try something that might help me out and get me a little more comfortable," he said. "I got away from it because there was a slight increase in concussions. It was proven in some tests. When Koyie [Hill] got called up, we got to talking about it, and he showed me they had redone some of the padding in the helmet and decreased the percentages. I decided to give it a shot.
"It felt a lot better [Monday]," Barrett said. "I'm trying to start somewhere to get comfortable defensively. Hopefully by starting there, I'll start swinging the bat better."
The hockey-style mask is heavier and in the summer, it can be very hot because heat is trapped in the helmet.
The advantages are that Barrett feels his vision is better with the hockey-style mask. He ranks ninth among National League catchers in throwing out baserunners, and has the second highest error total (five), which matches his total errors in 102 games last season. He's also been charged with eight passed balls.
"I'm not making excuses for anything," Barrett said. "[Switching masks] is just something that I think will help me be a little more relaxed and comfortable for now."
Extra bases: The Cubs' Interleague game June 24 at U.S. Cellular Field against the White Sox will be a day game. ... First pitch for the Cubs' June 30 game against Milwaukee has been changed from a 12:05 p.m. CT to 2:55 p.m. CT to accommodate FOX TV.
Minor matters: Ryan O'Malley gave up five runs on seven hits over 1 2/3 innings in Triple-A Iowa's 12-5 victory over Tacoma on Monday. The Iowa Cubs belted five home runs, including Micah Hoffpauir's 10th. Ronny Cedeno also homered. Eric Patterson had three hits. ... Mark Holliman threw three shutout innings in Double-A Tennessee's 8-1 win over Birmingham. Josh Kroeger had three hits. ... Mitch Atkins gave up five runs, four earned, on four hits and three walks over five innings while striking out seven in Class A Daytona's 7-6, 11-inning win over Dunedin. Tyler Colvin had three hits, including a pair of doubles, and scored three runs. He leads the league with 20 doubles. ... Robert Hernandez threw five shutout innings in Class A Peoria's 7-2 win over Beloit. Jim Adduci had three hits and Ryne Malone hit a two-run homer.
Peoria Chiefs pitchers Jake Renshaw and Alex Maestri were named to the Western Division roster for the 2007 Midwest League All-Star Game, to be played June 19 in Geneva, Ill., home of the Kane County Cougars. Pitcher Rocky Roquet also was selected, but he was promoted to Class A Daytona.
And a correction is in order. Peoria manager Ryne Sandberg has been ejected from three games this season, not two. Sandberg has been tossed in Chiefs games at Fort Wayne, Beloit and Cedar Rapids, and has yet to be tossed at home.
Project 3000: The Tennessee Smokies will hold Project 3000 night on June 16 at Smokies Park to raise awareness for Leber's Congenital Amaurosis (LCA), which has affected Derrek Lee's daughter, Jada.
The Smokies will hold a raffle and silent auction during the game. All proceeds will benefit Project 3000 and LCA research. Among the items available will be signed Cubs jerseys from Lee, Soriano and Carlos Zambrano; autographed bats from Lee, Aramis Ramirez and Matt Murton; and autographed baseballs from Lee, Murton, Soriano, Sandberg and Ryan Theriot. Fans also can bid on a Tennessee Smokies jersey signed by the entire team.
"The most important part of our effort is getting the word out and finding the 3,000 LCA patients," Lee said.
LCA is an inherited form of blindness or severe vision loss. Project 3000 is an effort to get anyone with LCA tested in hopes of finding a cure.
On deck: Zambrano will make his first start since his dugout skirmish in Wednesday's series finale against the Milwaukee Brewers. Zambrano is coming off a loss against Atlanta on his 26th birthday. First pitch is scheduled for 1:05 p.m. CT, and the game will be broadcast on WGN.
Carrie Muskat is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.