OAKLAND -- When Chris Bassitt was involved in the scary incident that saw him take a hard line drive off his face in Chicago on Aug. 17, the prospect of a return to the mound this season was considered a long shot. Bassitt, however, refused to buy into that notion.

Instead, before he even underwent surgery to repair several fractures near his right eye a few days after the injury, Bassitt assured his A’s teammates and coaches that he will make his way back before season’s end. After a long journey, Bassitt will be able to follow through on his promise.

Prior to Tuesday’s game against the Mariners, A’s manager Bob Melvin announced that Bassitt will be activated off the 10-day injured list in time to start Thursday’s four-game series finale at the Coliseum.

“I think initially, it’ll be like ‘Wow!’” Melvin said of his expectations for seeing Bassitt back on the hill. “After that, it’ll be like regular Chris Bassitt doing his thing out there. We’ll come full circle with him back on the mound. This is something that he’s been trying to get back to doing from the very beginning.

“To me, it’s kind of miraculous. But considering it’s Chris Bassitt, not so much.”

Miraculous is an adequate description. It was only a few weeks ago that Bassitt was struggling to perform normal everyday activities and unable to eat solid foods. But his determination allowed him to will his way back into the picture for the A’s.

It started with a bullpen session on Sept. 12. Three more throwing sessions over the past week followed that. The final signal to indicate Bassitt was ready came over the weekend in Anaheim, where he faced hitters in a simulated game at Angel Stadium.

“I’ve been ready,” Bassitt said. “It’s just a matter of there were a lot of boxes that needed to be checked. We finally checked them all off.”

How long Bassitt might be able to pitch in his first start back is still unknown. Melvin said the training staff will devise a target inning or pitch limit in the coming days, though it’s obvious that the bullpen will come into play at some point. To prepare, James Kaprielian, who was originally scheduled to start Thursday’s game against Seattle, will likely move to the bullpen as a possible backup for Bassitt on that day.

“We’ll see how it goes,” Melvin said. “Length is going to be an issue on that particular day. Knowing [Bassitt], it’s probably going to be us having to hold him back.”

Watching from the sidelines for over a month has not been a pleasant experience for Bassitt. Since his Aug. 18 placement on the IL, the A’s have gone 14-16 over that stretch to fall to a position in the playoff picture where they are now on the outside looking in.

Entering Tuesday, the A’s trailed the Blue Jays by two games for the second American League Wild Card spot with 12 games left in the regular season. Regardless of how the season ends, Bassitt will complete the mission he was on since his devastating injury, with a chance to build on a stellar All-Star campaign that has seen him go 12-4 with a 3.22 ERA and 154 strikeouts in 151 innings pitched across his first 25 starts.

He’ll also be returning with plenty of motivation.

“It sucked watching the way we’ve been playing,” Bassitt said. “It hasn’t been fun, especially sitting there thinking I can really help the team and not being allowed to. It’s been a little bit of a torture chamber. I’m happy to finally be back and, hopefully, help the team win.”