The 40-year-old will be gunning for an American Masters record this weekend.
Peter Berry suffered a fatal heart attack while on a run less than three weeks after the same thing happened to his brother.
The Olympian set a new facility record of 4:24.54 in the women's mile.
Plus, there is a $50,000 prize purse for the age-group Grand Prix.
The two men put on a show at the 2013 Millrose Games, with Sowinski breaking the American record.
The race is slated for Feb. 2.
Aaron Braun, who will make his marathons debut, leads the American men's lineup.
Inaugural grand prix tour includes six stops; total Tour prize purse exceeds $90,000.
The reigning London and New York City Marathon champion headlines a power-packed lineup.
There are eight men with sub-2:06 credentials, 12 women with sub-2:24 marks.