The A's bullpen is shaping up to be a major strength once again next season. Oakland will bring back All-Star closer Blake Treinen, Fernando Rodney and Lou Trivino, among several other relievers, and they signed two-time All-Star Joakim Soria to a two-year deal last week.

Still, the A's have hinted they might still add another arm in the 'pen, particularly a left-hander. Here's our market reset on the top relievers still available in free agency:

First tier: Zach Britton, Craig Kimbrel, Adam Ottavino, David Robertson

The big dominoes have yet to fall on the reliever market, but all four of these pitchers will be out of the A's price range. Kimbrel and Britton are likely looking at upwards of $15 million a year, and Robertson and Ottavino won't be far behind.

Second tier: Cody Allen, Brad Brach, Kelvin Herrera, Shawn Kelley, Tony Sipp, Adam Warren, Justin Wilson

Oakland has expressed interest in bringing Kelley back, and the feeling appears to be mutual. The 34-year-old right-hander was terrific last season after coming over from the Washington Nationals, posting a 2.16 ERA and 0.78 WHIP in 16 2/3 innings. However, Fancred's Jon Heyman projects Kelley to get $5 million, which may be a little more than the A's are willing to spend.

Allen, Brach, Herrera, and Wilson all figure to be out of Oakland's price range, but Warren and Sipp could be interesting options. Sipp would make sense as a second left-hander in the A's bullpen, joining Ryan Buchter.

The 35-year-old is coming off the best season of his career. In 54 appearances with the Houston Astros, he went 3-1 with a 1.86 ERA and 1.03 WHIP and notched 42 strikeouts in 38 2/3 innings. He was lights-out against left-handed hitters, limiting them to a .191 batting average and .557 OPS. Heyman projects Sipp to earn $5 million next season.


[RELATED: Examining the A's best starting pitching options left in free agency]

Third tier: Luis Avilan, Tony Barnette Jerry Blevins, Brad Boxberger, Tyler Clippard, Jorge De La Rosa, Jake Diekman, Zach Duke, Greg Holland, Bud Norris, Blake Parker, Sergio Romo, Hunter Strickland

This group presents a number of viable options for a reasonable price. The A's will likely focus on the southpaws, which narrows it down to Avilan, Blevins, De La Rosa, Diekman, and Duke.

De La Rosa, 37, had the best season of the five in 2018, finishing with a 3.38 ERA in 56 innings. He was especially effective late in the year with the Cubs, posting a 1.29 ERA in 17 games. For the season, left-handers hit .235 against him.

Duke, 35, was the best against lefties, allowing a .220 batting average and .602 OPS. Heyman projects him to earn $2 million next season, while De La Rosa will likely get between $2 million and $3 million.

Of course, the A's don't have to add anyone, as they already have a deep bullpen. That should allow them to negotiate from a position of strength.

Either way, expect Oakland to rely heavily on its 'pen once again in 2019.