SAN DIEGO - The Houston Astros have bolstered their bullpen by agreeing to an $18.5 million, three-year contract with Luke Gregerson and a $12.5 million, two-year deal with Pat Neshek, people familiar with the negotiations said Wednesday.

The people spoke on condition of anonymity because the deals with the right-handers were subject to physicals.

Gregerson, 30, spent five years with San Diego, then went 5-5 with a 2.12 ERA in 72 appearances for Oakland last season. Neshek, 34, has pitched for Minnesota, San Diego, Oakland and St. Louis. He was 7-2 with a 1.87 ERA for the Cardinals this year, when he struck out 68 in 67 1-3 innings and was picked for his first All-Star game.

Gregerson, who could take over as closer from Chad Qualls, receives $6 million next year and $6.25 million in each of the final two seasons.

Houston had shown interest in David Robertson, who agreed to a $46 million, four-year contract with the Chicago White Sox.

Neshek gets $5.5 million next year and $6.5 million in 2016. The deal includes an option at $6 million to $9 million, depending on his performance, with a $500,000 buyout.