The agreement would avoid arbitration and prevent Hernandez from becoming a free agent after the 2011 season. He is due in Seattle Thursday for a physical needed to complete the contract, a second person familiar with the talks said.
Seattle and representatives for the 23-year-old righthander exchanged proposed arbitration figures, with Hernandez asking for $11.5 million and the Mariners offering $7.2 million.
Hernandez was 19-5 last season, tied for the most wins in the major leagues, made his first All-Star team and had a career-high 217 strikeouts and career-low 2.49 ERA.
Lincecum asks for $13M
On the busiest day of baseball's offseason, 70 players eligible for arbitration reached agreements on contracts, leaving 39 still on track for hearings next month. That's a fraction of the more than 200 eligible for arbitration in November, the 128 who filed on Friday and the 46 who swapped figures with their teams earlier in the day.
Red Sox closer Jonathan Papelbon agreed to a one-year, $9.35-million deal, the highest salary for a reliever with at least four years of major-league service. Colorado reached a preliminary agreement on a three-year, $22.5-million deal with closer Huston Street.