The A's officially brought back a familiar face on Monday.
Free-agent right-hander Mike Fiers agreed to a two-year deal with Oakland. According to MLB.com's Jon Paul Morosi, the contract is worth approximately $14 million to $15 million.
Fiers, 33, went 5-2 with a 3.74 ERA over 10 appearances (nine starts) down the stretch in 2018. He helped the A's make their surprising run to the American League Wild Card Game after Oakland traded two Minor League prospects to acquire him from the Tigers in an August waiver deadline deal. 
The 2018 season was one of the best of Fiers' eight-year Major League career as he finished with a 3.56 ERA and 1.18 WHIP across 31 appearances (30 starts) with Detroit and Oakland. The A's non-tendered Fiers last month when he was set to make nearly $10 million in 2019 through arbitration, per MLB Trade Rumors, and so now Oakland was able to sign him back for a lower average annual salary next season.
Even after bringing back Fiers, the A's appear to have more work to do in regard to their starters. Oakland's 2019 rotation is still wide open as Sean Manaea recovers from arthroscopic shoulder surgery, Andrew Triggs recovers from thoracic outlet surgery and Jharel Cotton and A.J. Puk both recover from Tommy John surgery.
A's executive vice president of baseball operations Billy Beane said in a conference call Monday that starting pitching will continue to be the club's priority as the offseason continues.
"Right now, the focus from here to Spring Training -- and possibly through Spring Training like last year -- is we're gonna continue to try to find some starters to bring into camp," Beane said. "We like a lot of the club that's on the board right now. We feel very good about the position players. We feel very good about the bullpen. It's all about the starters right now."
Currently, righty Daniel Mengden and now Fiers look like the only holdovers from the A's season-end rotation who could be ready to pitch for Oakland by Opening Day.
"We need to create even more options for [manager Bob Melvin] and [pitching coach Scott Emerson]," Beane said. "We also need to provide some depth, too. We know -- and we faced it last year -- guys are going to go down during the season."
That doesn't mean the A's are going to be overaggressive in their pursuit of free-agent starting pitching.
"We sort of have to be opportunistic, but also somewhat patient," Beane said. "We'll probably wait it out and see who are the best options. In some cases, there are gonna be some guys that find this an attractive place to pitch -- because it's a very good young team, it's a good park to pitch in. Some guys may find coming to Oakland is the right move for them, and we'll certainly search those guys out as well."
The A's do have one especially interesting internal option for the rotation: top prospectJesus Luzardo. The 21-year-old is ranked the best left-handed pitching prospect in baseball by MLB Pipeline, and the No. 12 prospect overall.
"He's a very talented kid," Beane said. "At this point, we're the caretakers of his career. Historically, we've always wanted to make the decision on guys like this, that when they come up, they stay up. We'll just have to make that call during the spring or sometime at the beginning of the season.
"It's hard to answer now, but he's a very talented guy and we certainly expect him to have an impact at some point during 2019. Whether it's at the start of the year, the middle of the year or the end of the year, we'll have to wait and see."