Armstrong had hoped to accompany Samuelson to the finish line as she did for him by running the final miles of the 2006 New York City Marathon, but the rules do not allow him to do so and he could decline to run.
Samuelson, 52, is running the race to commemorate the 25th anniversary of her landmark gold medal in the 1984 Olympic marathon, but she is also eyeing an age-group record in the race. To be eligible for a record, she can have a pacesetter. But were Armstrong to run as one, he would have to begin the race at the start; he cannot jump in at a later point.