Abad could help bolster a talented bullpen that likely has lost closer Grant Balfour in free agency, with the ninth-inning spot expected to be filled from within by Sean Doolittle or Ryan Cook. General manager Billy Beane and manager Bob Melvin believe they have options in-house to close out games for the two-time reigning AL West champion A's.
The 27-year-old Abad, who was designated for assignment last Wednesday, went 0-3 with a 3.35 ERA in 39 appearances for the Nationals last season. He spent 2010-12 with the Houston Astros and has a career record of 1-14 with a 4.56 ERA in 127 outings.
Wooten batted .257 with 20 home runs and 69 RBIs for Class A Beloit this year. He was a 37th-round selection by Oakland in the 2012 amateur draft out of East Carolina. The Nationals said he won't be added to their 40-man roster but will join the club's minor league system.