The update came mere days after Carter made a public appearance at his charity golf tournament in West Palm Beach, Fla., exchanging greetings with several of his former teammates.
Nationals and former Mets manager Davey Johnson, who attended the event, lamented that Carter seemed so weak during the event that he could not get out of his chair.
"All the treatments have really pulled up on him, but he's a fighter," Johnson said. "I look for him to fight through it."
Like Carter's daughter, Kimmy Bloemers, who has maintained an online journal of her father's progress throughout the past eight months, many of the catcher's former teammates pointed to Carter's playing career as evidence that he can persevere.
But with Carter's condition declining, his friends are also preparing for the worst. Carter delivered a brief speech at his charity dinner last weekend, thanking his attendees for their support in what Teufel described as a "Lou Gehrig-ish" address.
"You put things in perspective a little bit more when you have something like this," Teufel said. "He's just very thankful at this point for what he's had.
"It hurts to see time creep up on him like that and grab him a little bit. He's only 57 years old. We're just saddened by all of it."
Teufel, Johnson and other members of the 1986 Mets gathered Tuesday at the Marriott Marquis in Manhattan to support the 23rd B.A.T. dinner, which annually raises funds to support former baseball players in need. Other former teammates, including Dwight Gooden and Darryl Strawberry, were also scheduled to attend.
Bloemers and Carter's two other children had made an emotional appearance three days earlier at the New York chapter of the Baseball Writers' Association of America's annual awards dinner, accepting the Milton and Arthur Richman "You Gotta Have Heart" award on behalf of their father.
But outside of his recent golf tournament speech, Carter's public appearances have been rare. Former Mets outfielder Gary Sheffield, Gooden's nephew, recalled seeing Carter at a charity event in Toronto just prior to the catcher's original diagnosis. That event consisted of about a half-dozen softball games and Carter participated in each one of them.
"He was normal," Sheffield said. "It just goes to show you to appreciate life.
"All I do is just say prayers for him every day."
That seemed to be a common thread among teammates who, for the most part, consider Carter a friend first and teammate second.
"It feels like someone just punched me in the chest," former pitcher Sid Fernandez said. "It's hard to take, especially when you know someone so well. He wasn't my father, but he was almost like a father figure to me."
Another former teammate, Wally Backman, also attended Carter's tournament and dinner last weekend, calling him "a brother to a lot of us."
"I don't know if anybody ever said anything bad about Gary," Backman said. "For him and his family, it's been a tough road, and it was tough this last weekend seeing Gary. But you've got to wish him the best."