MESA, Ariz. -- A’s catcher Sean Murphy remembers waking up one morning in late January to tightness in his chest that had been lingering for a few days. Given the symptom, Murphy figured he may have contracted COVID-19 and drove to a hospital near his home in Dayton, Ohio.

Turns out the situation was a bit more dire.

Upon his arrival to the medical center, Murphy was taken to get X-rays on his chest. It was during this process when doctors discovered that he had a collapsed lung that required immediate surgery. The official diagnosis was spontaneous pneumothorax, which is described as a formation of small sacs of air in lung tissue that rupture and cause air to leak into the surrounding areas of the lung. The cause? That remains a mystery.

“We don't really know,” Murphy said. “I can't pinpoint anything. It may have been a hard cough I had in my sleep. But honestly, it just sometimes happens.”

The news came as a shock to Murphy, and the procedure he would have to undergo only made the situation even more daunting. The 26-year-old backstop required a tube to be placed in his chest so that the lung could re-expand.

“That [surgery] was just to make sure my lung didn't collapse and kill me, basically,” Murphy said. “So that one had to be done.”

After completion of the surgery, doctors then told Murphy of a second operation that while not necessary, was recommended to avoid a recurrence of the issue. One of the risk factors for recurrence included flying on an airplane.

“The second surgery is where they essentially prop up the lung against your chest wall, and it decreases the chance of it happening again,” Murphy said. “We decided to go with that because of how much we fly. For my own peace of mind, I decided to get the surgery to just not be worried every time the plane takes off.

“We went back and forth on whether or not we would get this optional one. We decided that peace of mind was a little more valuable.”

Now in camp after missing the start of Spring Training earlier this week, Murphy is getting in as much work as he can on a limited workload. He is still a few days away from being able to hit as he awaits the healing of some leftover scar tissue on his ribs from the surgeries. In the meantime, Murphy has been catching balls from pitching machines and doing strength training in the weight room.

As for a possible return to game action, Murphy expects to be ready by Opening Day -- a timeline that was deemed feasible by the doctors and surgeons who repaired his lung -- with the hope that he can play in games near the end of the Cactus League schedule next month.

“It’s more relief as I'm starting to feel much better,” Murphy said. “Couple weeks ago, I felt terrible recovering from surgery and I think I feel really well now. Certain things have turned around. I feel great moving. Obviously, I want to be out there, and there's frustration. But at this point, it’s more relief that I feel so good.”

A’s manager Bob Melvin has been surprised at Murphy’s quick progression given how recently the surgery was performed. Though Murphy’s workload could be scaled back early on in the regular season -- as was the case last year when he was making his way back from knee surgery -- Melvin is also sticking to Opening Day as a realistic possibility.

Murphy’s availability is of great importance for this A’s club. He enjoyed a breakout rookie campaign last year, leading the A’s in OPS (1.062) and home runs (five) over the final month of the season as he slashed .277/.424/.638 across 16 games in September. He also showed off his power in the postseason with a pair of home runs, including an important two-run homer in an American League Wild Card Series-clinching Game 3 against the White Sox.

“We’re still at the same timetable for him to be ready to start the season,” Melvin said. “At the time, it was shocking to me. It just felt, obviously, a lot bigger than baseball. Next thing you know, he’s driving down here trying to get ready for the season. It’s nice to be young."