Four-time Iditarod Trail Sled Dog Race champion Martin Buser said Wednesday he will "definitely run" this year's 1,000-mile race to Nome, several weeks after a four-car pileup in Seattle sent his eldest son, Nikolai, to the hospital with critical injuries.

Buser said Nikolai, 27, has made tremendous progress since the crash on Jan. 22. He said his son once had 80 tubes and wires connecting his body to various machines, but the only ones remaining are tubes in his nose that deliver oxygen — and they're only there occasionally. He can talk, eat and drink on his own, allowing him to move to the hospital's fourth floor for rehabilitation after several surgeries, Buser added.

"That's a huge progression," he said. "We're so ecstatic."

Still, as Buser puts it, the "race isn't over." Nikolai needs to rebuild muscles. He needs to learn to walk again. So far, the best he's done is a few trips around the hospital in a wheelchair, Buser said.

He talked about his family and the Iditarod Wednesday afternoon from Seattle. Since the crash, he and wife, Kathy Chapoton, have camped out in Nikolai's hospital room. They joke that "the gypsies have moved in," Buser said, with each taking take a shift: Kathy normally on days and him at night, which he sometimes calls the "Iditarod shift — which means you take the day shift and the night shift, but I do take a nap in the late afternoon."

Meanwhile the couple's youngest son, 26-year-old Rohn, remained in Big Lake to take care of their 90 dogs at the family's Happy Trails Kennel.

Rohn withdrew this week from the Iditarod. He did not respond to messages Wednesday, but Buser said his son's decision to withdraw was "just a personal choice." He said Rohn has taken on much more work at the kennel since Nikolai's crash. He's also had difficulty training the Iditarod dogs during this winter's warm days, Buser said.

Iditarod race director Mark Nordman said James Volek will take Rohn's spot in this year's field of 86 mushers. Volek ran the Iditarod in 2013, placing 52nd. Volek has also worked at the Big Lake kennel as an apprentice since late summer, Buser said. He will run Rohn's dog team and Rohn will likely swap places with his father in Seattle during the race as Buser races his 31st consecutive Iditarod.

Immediately after the crash, Buser said he didn't know if he would make it back to Alaska for the March 5 ceremonial start in Anchorage. Not until his son moved to the hospital's fourth floor did he start to seriously think about the race, strategy, dogs and equipment.

"We love our dogs very much, but as a family, we love our kids even more," he said.

Buser and his wife named their two sons after Iditarod checkpoints. While Nikolai attended the University of Washington and later moved back to Seattle, Rohn stayed close to the kennel and ran his first Iditarod in 2008 as a senior in high school. He ran the race again in 2012, placing 18th, and in 2015, placing 40th.

Over the past several weeks, Buser said many friends have shown up both in Seattle and Big Lake to help the family — feeding dogs and bringing hot meals. He said when 2011 Iditarod champion John Baker's sister prepared food for her brother's drop bags along the trail, she also prepared some for Buser.

"Totally unasked for, but incredibly appreciated," he said.

Buser said he doesn't know when he will fly back to Alaska, but it probably won't be "until the very last moment."