Neshek will get a $16.5 million, two-year contact pending a successful physical. The person spoke on condition of anonymity Monday because there was no official announcement on the agreement.
The 37-year-old Neshek was an All-Star last year in his first season in Philadelphia. The Phillies then traded him to playoff-contending Colorado in late July for three prospects.
The side-slinging righty was a combined 5-3 with one save and a 1.59 ERA in 71 games. He had a 1.12 ERA in 43 games for the last-place Phillies.
Neshek has played 11 seasons in the majors, also pitching for Minnesota, San Diego, Oakland, St. Louis and Houston.