SAN FRANCISCO -- Shota Imanaga was critical of his performance against the Giants on Thursday afternoon. The Cubs lefty pointed to the three runs he surrendered in the sixth inning and explained that he needed to work on improving upon what went awry in that frame.

The reality is that Imanaga spun a quality start, one of the allowed runs came on a slow infield roller that eluded three fielders, and the pitcher positioned the Cubs to escape Oracle Park with a 5-3 victory in 10 innings.

Through a consistent wave of injury setbacks, Imanaga has been a steady presence and source of wins for a Chicago team in search of them.

“He’s been fantastic,” said outfielder Ian Happ, whose two-run homer in the 10th helped the Cubs salvage a win in the four-game set. “It’s been such a stabilizing force for us.”

Imanaga may have walked away with a no-decision for his six-inning effort, but the Cubs improved to 12-3 on his start days this season. For perspective, Chicago has gone 26-41 in its other games this year. Not only has Imanaga pitched superbly -- aside from two outings that account for 17 of the 29 earned runs on his season line -- he has stayed healthy.

Prior to the finale in San Francisco, the Cubs placed righty Javier Assad on the 15-day injured list due to a right forearm extensor strain. Assad joined lefty Jordan Wicks (right oblique) and righty Ben Brown (neck strain) on the shelf.

Wicks is rehabbing in Arizona and is expected to be out until after the All-Star break. Brown got back on a mound Wednesday for a bullpen session in the early stages of his build-up. Injuries have not been limited to those three Cubs starters, either. Each member of the rotation has spent time on the IL.

Kyle Hendricks (back) was out for roughly three weeks between April and May. Jameson Taillon (back) started the year on the IL and returned in late April. Justin Steele sustained a left hamstring injury on Opening Day and missed the next month. Wicks had a prior IL stint due to a left forearm setback. Caleb Kilian, who was a planned depth piece, had a right shoulder injury in Spring Training that cost him the first half.

“Look, it's part of every team's season,” manager Craig Counsell said. “Obviously, as we get players back, we lose a player. And so, we're kind of thin always. You've just got to deal with it and manage it the best you can.”

The players have also tried to maintain some perspective as the injuries have piled up.

“Some guys are getting opportunities that we normally wouldn't get,” Cubs pitcher Hayden Wesneski said. “Injuries are not good. The next guy has to step up, and there's a lot of learning that's going on. The hope for the long-term, especially for playoffs and stuff, is that this will help out to have 13 guys able to pull all one direction.”

The preseason injury to Taillon paved the way for Assad to make the Opening Day rotation. Brown found his way onto the Cubs’ pitching staff -- moving between the rotation and bullpen as needed -- when Steele landed on the IL.

Following a stint in the ‘pen, Wesneski is getting another chance as a regular starter with Assad sidelined.

Within the relief corps, the Cubs are also operating without four experienced arms. Right-handers Mark Leiter Jr. (right forearm strain), Adbert Alzolay (right flexor strain), Julian Merryweather (rib stress fracture) and Yency Almonte (right shoulder strain) are all on the IL right now.

That has created opportunities for the likes of Luke Little, Porter Hodge and Tyson Miller, among others. In Thursday’s win, Little and Miller covered the seventh and eighth, respectively. Hodge worked the 10th, staving off a San Francisco rally and picking up the first save of his career.

“I'm really proud of Porter Hodge,” Counsell said. “It's the biggest moment, the biggest spot he's pitched in since he's been here and he handled it great.”

All that pitching depth the Cubs raved about going into the season?

“It’s definitely being put to the test right here,” Wesneski said.

Imanaga hopes to continue to play his part as a rotation stabilizer.

“Nobody wants to get hurt. It just happens,” Imanaga said via interpreter Edwin Stanberry. “Everybody wants to perform at a high level. Injuries happen, but once everybody comes back, and we're healthy again, I think my job is to make sure the team keeps on winning.”