Trade grades: Sean Manaea an upgrade for Padres' rotation, but how long will he be in San Diego?

Darren Yamashita-USA TODAY Sports

It was only a matter of time before the Oakland Athletics continued their offseason purge and they traded one of their two remaining veteran starters. On Sunday, the A's sent left-hander Sean Manaea and minor league pitcher Aaron Holiday to the Padres for two prospects, infielder Euribiel Angeles and pitcher Adrian Martinez.

The only surprise is the Padres being the team receiving Manaea since they already have Yu Darvish, Joe Musgrove, Blake Snell, Mike Clevinger, Chris Paddack, Nick Martinez, Dinelson Lamet, Ryan Weathers and MacKenzie Gore as rotation options. Why would they want another starting pitcher?

Two possibilities here: