(CNN) -- Steel tubing has begun to be placed to reinforce the path that connects the 33 miners trapped in Chile to the surface, the final step before the extraction of the miners can begin, Mining Minister Laurence Golborne said Sunday.
Three of the tubes are already in place, he said. About 15 or 16 tubes will be placed in total.
"We are expecting no major problems," Golborne said
If all goes according to plan, the first of the miners could be pulled from the mine by Wednesday, he said. But the health and safety of the miners remained the top priority, he added.
Given their circumstances, the miners, who have been trapped since August 5, are in "very good" health, Health Minister Jaime Manalich said. Their spirits also remain high, he said.
When he told the miners through video conference that they would have to choose an order to be rescued in, there was no shortage of volunteers to go last, Manalich said.
"They continue to have an admirable attitude," he said.
The last six hours before the rescue starts, the miners will be switched over to a liquid diet and vitamins ahead of their trip to the surface.
The change in diet is one way that officials are trying to mitigate some of the challenges associated with the rescue. These include the loneliness of being in the rescue capsule, and dizziness and panic because the capsule will spin around as it rises, Manalich said.
After the 2,300-foot hole in Chile is secure, materials and equipment will be brought in so that the rescue capsule -- dubbed the Phoenix -- can be lowered into the mine. Then, authorities will lower a doctor and a rescuer into the chamber, Manalich said earlier. Medical and rescue personnel will be in place to start extracting and treating the miners.
Once the men have been extracted, they will undergo about two hours of health checks at a field hospital set up at the mine. They will then be flown by helicopter to a hospital in the town of Copiapo -- approximately a 15-minute flight.
Miners who are healthy enough will be allowed to visit briefly with family members in a reunion area before being taken to the hospital.
Health officials have increased the miners' physical activity in recent days to gauge how they can handle the stress of being removed.
The overall response has been good, though some miners have exhibited anxiety or have had minor cardiac issues, Manalich has said.
The miners have been in contact with the outside world through a small bore hole that sends them food, water, supplies and other necessities.
CNN's Karl Penhaul and Patrick Oppman contributed to this report.