"Hopefully, we'll get him back, but I think it's probably less than 50-50," Piniella said before Saturday night's game with Oakland. "We're not sure. We don't know."
The Mariners had rookie Ramon Vazquez, who was called up from Triple-A Tacoma on Sept. 7, in their starting lineup at shortstop again Saturday night. Mark McLemore, Guillen's backup who has played six positions for Seattle this season, has a sore knee and isn't expected to be able to play until Tuesday night.
The AL West champions will open the playoffs Oct. 9 at Safeco Field.
Piniella said he wasn't ready to write Guillen off for the playoffs, though.
"I'm not at that stage yet," he said.
The Mariners were stunned when Guillen was diagnosed with tuberculosis. They knew he was sick, but they had no idea how sick he was. They found out after they got X-rays back before Friday night's game, a 5-3 victory over the Athletics. Guillen went to a hospital Thursday on the team's off day to find out why he was feeling so poorly.
"This was a total surprise yesterday," Piniella said. "We were told yesterday he had TB, it was basically a total surprise. I never contemplated that possibility."
Although Guillen had been ill, he hadn't complained to Piniella or the Mariners' coaches. But the Mariners had to take him out of the lineup in a couple of games because he had nose bleeds.
Mariners doctors thought Guillen could have been suffering after effects from a collision with left fielder Al Martin in a game May 19. Martin sustained a concussion in the collision.
"We didn't know what it was," Piniella said. "Every day he came to the ballpark he said he was ready to go. He's a tough kid."
Piniella said he was happy to see Guillen, 25, from Venezuela, go to the hospital. The player has been quarantined.
"That's the best thing for him," Piniella said. "I hope he stays there for a couple or three days."
Mariners players will be tested Thursday to see if any of them have contracted tuberculosis. But none of them has showed any symptoms of it, Mariners physician Dr. Mitch Storey said.
Because tuberculosis is a contagious disease that spreads through the air like the common cold, the Mariners players were concerned about their own health and the health of their children.
"Most of the guys are concerned about their kids," center fielder Mike Cameron said. "I don't want to tell my wife about it because she'll go ballistic. We all fly together and Carlos has been sick for a while."
After Friday night's announcement, Storey of the Mariners said the team was hopeful Guillen would be able to play in the playoffs.
"But if everything goes well, we hope Carlos will be playing in one week and we anticipate him to be available for the playoffs," Storey said.
Countryman Freddy Garcia, who won his career-best 18th game Friday night, and reliever Jose Paniagua, Guillen's close friend from the Dominican Republic, were distressed about Guillen on Saturday night. Garcia pitched Friday night after finding out about Guillen's diagnosis.
They talked to him Saturday, and both said they planned to visit him at the hospital.
"He doesn't feel good," Garcia said. "I told him to take it easy and everything will be all right. But he wants to play. He wants to come back."
Paniagua said Guillen had been sick for about three months and had told him he suspected the blood he was losing was from his lungs and not his nose.
"I had a couple of cousins die in the Dominican from TB," Paniagua said. "I didn't sleep very well last night because I was worried about Carlos. I got up five or six times during the night."
Guillen will be given antibiotics for the next six to nine months.
"He will probably be feeling much better in two weeks," Storey said. "The day you start taking antibiotics, the amount of infected bacteria actually in your system starts decreasing. But he will need to take antibiotics for a long time. This is the kind of bacteria that is difficult to eradicate."
Guillen came to the Mariners on July 31, 1998, along with Garcia and left-hander John Halama in a trade that sent Randy Johnson to the Houston Astros. Guillen became Seattle's regular shortstop last winter, after Rodriguez left as a free agent to go to the Texas Rangers.
He's been a key player for the Mariners this season, particularly in the field, where he committed only 10 errors in 140 games. He's batting .259 with five home runs and 53 RBIs.
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