One of the biggest needs for the A's this offseason is adding some veteran arms. The pitching staff was filled with inexperienced arms in 2026, and it really showed, as the team finished with the worst bullpen ERA in all of baseball.

The offseason has just begun following the Brewers' first World Series Championship. Following the win, the A's have poached Cam Castro from the Brew Crew to become their new general manager.

Castro became the team's GM on Wednesday, and they have been without a true GM for a few months since they mutually parted ways with David Forst.

Now that the A's have a new President of Baseball Operations and GM, they will work together to add some pitching to the needy staff. The first thing they can do is look to add this veteran arm to their bullpen.

Blake Treinen Could End His Impressive Career With the A's

Treinen, 38, is certainly coming towards the end of his career. He's played with the Dodgers for the last six seasons and has also spent four years with the Nationals and three years with the A's.

His career has been quite impressive. He is a former All-Star and a three-time World Series Champion. The right-hander holds a career 2.94 ERA in 606 innings pitched.

Arguably the best season of Treinen's career came when he was part of the A's in 2018. He made his only All-Star appearance, posted 38 saves, and posted an amazing 0.78 ERA in 80.1 innings pitched. He finished sixth in Cy Young voting and 15th in MVP voting.

Now he can end his career in the place where he had his best season. The A's are in dire need of experienced arms, and Treinen proved this season that when he's healthy, he can still be a good arm coming out of the bullpen.

Treinen Could Serve As the Team’s Closer

Since the A's bullpen isn't so great, the team doesn't really have a true closer. Elvis Alvarado served the role for a while this season, but he might be too inconsistent to be a closer for a playoff team.

If the team could move Alvarado to a setup man, or even a middle reliever, and land a true closer, they could set themselves up to have a much stronger bullpen in 2027.

We have already discussed how David Bednar and Alex Vesia could come in to be the A's closer, but both options could cost the A's a lot of money. If they want to save some money and get Treinen, he could still be a solid option if he can stay healthy.