Richardson, 72, has been at Carolinas Medical Center since last week, when he was admitted after complaining of not feeling well. Richardson, who received a pacemaker/defibrillator in June, also had coronary bypass surgery in October 2002.

While the pacemaker/defibrillator is working effectively, according to a statement released Wednesday by the Panthers, Richardson was readmitted to CMC last week when he began to feel poorly and underwent several medical tests.

The team had no comment beyond the news release, but NFL spokesman Greg Aiello said, "The entire NFL team is thinking of Jerry and his family."

The news comes during a week when excitement swirls around Richardson's first-place team, which is 10-3 and won a big game on Monday Night Football against the Tampa Bay Buccaneers.

At CMC, the median waiting time for an adult on the heart transplant list is about 2.1 months, according to spokesman Scott White. The hospital has performed 428 heart transplants since it started the program in 1986.

CMC's success rate for heart transplants is similar to those reported nationally, according to data collected by the Organ Procurement and Transplantation Network.

Of 38 patients who received heart transplants at CMC from July 1, 2004 to Dec. 31, 2006, 95 percent survived after one month, and 89 percent after one year, the data show. In that same group, two patients died within one month and four within one year.

Richardson, a native of the tiny eastern North Carolina town of Spring Hope, is the first former NFL player to own a team since the Chicago Bears' legendary George Halas.