Cole made $6.75 million last year, when he earned his second All-Star selection and went 15-5 with a 2.88 ERA. He earned $6.75 million.
Arbitrators Gil Vernon, Steven Wolf and Walt De Treux heard the case Monday and are expected to decide later this week.
Players and teams have split six decisions, including a victory for Astros shortstop Carlos Correa. The case of Cleveland pitcher Trevor Bauer is pending.
Four more hearings are scheduled this week, for Michael Fulmer of Detroit, Aaron Nola of Philadelphia, Luis Severino of the New York Yankees and Alex Wood of Cincinnati.