OAKLAND -- Marco Estrada could function as a barometer for the A's fortunes this year.

Though Estrada opened this season with a career record near .500 (62-66), his results aren't stuck in neutral.

Estrada can excel, as he did in 2015 when he finished 10th in the American League Cy Young Award voting while pitching for Toronto. He followed that up during the next season, when he was named to the AL All-Star team.

Estrada has offset that effectiveness with disappointing performances. He led the National League with 29 home runs allowed while toiling for Milwaukee in 2014. He posted a 5.27 ERA with Toronto over the last two seasons.

Estrada's erratic tendencies didn't bother the A's, who dipped into free agency to sign him to a one-year, $4 million deal. They believe that Estrada, 35, can regain his best stuff and help the A's remain contenders.

The A's own a reputation for resuscitating pitchers' careers. Starters such as Trevor Cahill, Rich Hill, Edwin Jackson, Scott Kazmir and Brett Anderson regained effectiveness in Oakland. The A's strongly believe that Estrada also looks primed for a turnaround.

"Last year, he pitched through some back and hip issues and lost a little bit of velocity," A's general manager David Forst said. "But his command is as outstanding as ever. His changeup has always been one of the best pitches in the league. He's a guy we fully expect to bounce back and be near the top of our rotation for 2019."

That hip ailment particularly hampered Estrada.

"I'm feeling much better," he said recently. "It was tough. I probably shouldn't have tried to pitch through something like that, but I'm glad I did. It didn't go the way I wanted it to, but I still went out there and made the starts, so I'm happy about that. I'm hoping to be a little smarter about things like that."

Entering the season with a mostly unproven starting rotation, a strong season from Estrada is almost imperative if the A's are to succeed. A's slugger Khris Davis, a teammate of Estrada's in Milwaukee, believes the right-hander will thrive in his new surroundings.

"He brings that experience, and he's going to work some innings," Davis said. "He's a competitor, and he pitches to win. That's the most important thing. He's a team guy, and playing with him in Milwaukee, that's what he taught me. It's not about himself."