MESA, Ariz. -- The Cubs are looking for two starting pitchers this spring and at least one of those is expected to be a left-hander, which means Sean Marshall and Tom Gorzelanny have a good shot.

The three starters who are set are right-handers Carlos Zambrano, Ryan Dempster and Randy Wells, who will kick off the Cactus League opener Thursday against Oakland. Ted Lilly is rehabbing from arthroscopic surgery on his left shoulder, performed in early November, and may not be ready until mid-April or early May. That creates two vacancies.

Besides Gorzelanny and Marshall, the other candidates for the two spots include right-handers Carlos Silva, Jeff Samardzija and Rule 5 Draft pick Mike Parisi.

"The pitchers have a wonderful opportunity in this camp, first of all, to get a starting spot, and second of all, to work their way into the bullpen," Cubs manager Lou Piniella said Sunday.

Silva, 30, acquired from Seattle, is the veteran of the group but is coming off two tough seasons in which he went 5-18.

"I told him [Saturday] he threw the ball very well," Piniella said of Silva, who faced live hitters at Fitch Park. "He's keeping the ball down, he had some movement on his sinker. He threw a few changeups, and he was getting his breaking ball over the plate.

"There's no reason for this guy not to be able to bounce back and be a fifth starter for you. He pitched in Minnesota quite well to warrant a four-year deal that all of us would've been very happy with. He's got a wonderful opportunity over here to re-establish himself."

With the Twins, Silva was 14-8 in 2004, 11-15 in '06, and 13-14 in '07, then signed a four-year, $48 million deal with the Mariners.

Gorzelanny, 27, was 4-2 with a 5.63 ERA in 13 games after joining the Cubs last season from Pittsburgh. Marshall, 27, has been the most versatile Cubs pitcher the past two seasons. He has a 4.37 ERA in 35 starts since the beginning of the 2007 season. Last year, he was 2-5 with a 5.24 ERA in nine starts, and 1-2 with a 3.23 ERA in 46 relief appearances.

Parisi, 26, does have some Major League experience. He appeared in 12 games with the St. Louis Cardinals in 2008, including two starts. He's coming back from Tommy John surgery in August 2008.

Samardzija, 25, made his first big league start last year, appearing in 20 games with the Cubs. He's shown the most improvement this spring among the young pitchers.

Once the games begin, the competition starts in earnest.

"We've got some good arms here," Piniella said. "There's no reason we can't put together a nice solid five until we get Lilly back. I couldn't tell you what the combination will be. Same thing with the bullpen. We have some good young kids here with nice arms but very limited Major League experience. We have to see how they throw and how they respond."

The Cubs did get encouraging news on right-hander Angel Guzman, who has been held back because of soreness in his right shoulder. He threw 25 to 30 pitches from 45 feet on Sunday in the batting cage to avoid the rain -- which shortened the day's workout -- and passed all the tests. If he feels OK on Monday, Guzman will throw again.

John Grabow was the only pitcher scheduled to face live hitters on Sunday, and he got his work done despite the rain. The position players met with hitting coach Rudy Jaramillo, and the pitchers had a session with Larry Rothschild.

"If we were going to lose a day of work," Piniella said, "today was as good a day as any."