Cook induced a quick groundball from Jose Altuve and a fly ball to shallow center from George Springer, before he got former teammate Jed Lowrie swinging on strikes.
"That was good to see. He threw strikes, he was throwing hard again," said A's manager Bob Melvin. "Had the part of the order where he had to be good, and he got it done in minimal pitches. Thrown right into the fire in the seventh inning. Today we told him, 'That's probably going to be your inning, whether it's tied or ahead.' He was ready for it and did well."
"Just getting back to being myself and throwing the baseball the way I know I can," said Cook. "I feel confident in all my pitches right now, so hopefully I can get on a roll and help the team in whatever way they see fit."
Cook began the season with Triple-A Nashville after continued spring struggles. He posted a 16.88 ERA in five Cactus League games with the A's but rebounded in the Minors, compiling 5 2/3 scoreless innings with just one hit allowed for the Sounds.
"You look at the numbers, he certainly had a good time of it down there," said Melvin. "And this is a guy that's been an integral part of our bullpen since 2012. He just had a tough time during Spring Training and needed to regroup a little bit and work on some things.
"It's nice to have him back, because we've been in flux in our bullpen, whether it's without him, Sean Doolittle, and having to try to search for guys pitching in different roles. Hopefully this is the first step in getting our bullpen back in sync."
• Coco Crisp, on the mend from right elbow surgery, could be taking live batting practice by the end of this week. The outfielder continues to make quick progress and is expected to engage in a short rehab stint ahead of his potential May return.
• The A's signed veteran Ryan Roberts to a Minor League deal this weekend. Roberts, who was released by the Royals during Spring Training, is a career .243 hitter in nine big league seasons.
Roberts lends the organization added depth in the wake of Tyler Ladendorf's trip to the Minor League disabled list with a left ankle sprain.
"He's a guy that has a pretty good history of hitting left-handed pitching, is versatile, can play the outfield, multiple positions in the infield," said Melvin. "For us, I think it's a good pickup to have, especially with Ladendorf being hurt at this point."