The veteran cleared his final hurdle, a Saturday afternoon bullpen session in Colorado, and the team confirmed the decision immediately afterward.
Richards made seven Minor League rehab starts, including two for Class A Advanced Lake Elsinore in the California League playoffs. But he hasn't gone past 63 pitches, and manager Andy Green indicated Richards would be on a similar short leash down the stretch.
Here are five thoughts on what Richards' long-awaited return means for the Padres:
1. The rotation just got better
How much better? That's TBD. We probably won't get a solid idea until next spring. It's patently unfair to judge Richards on two or three starts in 2019.
"You just take the confidence that he's been back on the big league mound, and he's competed," Green said. "The results, yeah, he wants results, and we want results for him. But I don't think we're going to read too much into what the box score says. We're confident in who he is and who he's been in his career."
A quick refresher of who, exactly, Richards has been: Since 2014, his 3.15 ERA ranks 12th among all pitchers with at least 500 innings. Sure, he's been slowed by injuries. But when healthy, Richards can be downright unhittable.
Just ask Wil Myers, who went 0-for-5 with three strikeouts against Richards.
"He’s really good," Myers said. "He’s as tough as anyone on righties. I think we're all excited to have him back and throwing for us."
2. The Padres still need more pitching
Richards might be part of the solution. But he definitely isn't the solution.
San Diego's 4.63 rotation ERA ranks 17th in the Majors. That mark is 5.06 in the second half, as attrition has taken its toll on some young starters.
The Padres' offseason plan seems simple enough: Add starting pitching. Whether that's a frontline arm or back-end depth, the Padres could use more.
"We're always going to be on the lookout for [pitching]," general manager A.J. Preller said last month. "We'll get to the offseason, and it'll still be a focus."
3. The 2020 rotation race just got tighter
The Padres didn't commit $15.5 million to a rehabbing Richards without planning to use him. Barring a setback, Richards has his place locked up in the Padres' 2020 starting rotation.
With the Padres expected to return to a more traditional five-man staff in 2020, that latter group likely will be fighting for two spots -- and perhaps only one if the Padres hang onto Lucchesi while adding a frontline arm.
4. So far, the Padres' investment is paying off
The Richards signing was a clear gamble from Preller. Over the previous three seasons, Richards had missed time with a knee ailment and two elbow injuries. He made only 28 starts in that span.
Undeterred, the Padres spent a significant sum to land him. The deal signified a commitment toward contention in 2020. But it came with its share of risks.
So far, so good. Richards was rusty at times in the Minors, often struggling with his command. But his mid-90s fastball velocity returned relatively quickly. Reportedly, so has the elite-level spin on his fastball and breaking pitches.
If Richards can stay healthy and resemble the version of himself from the past decade with the Angels, that risky contract might end up looking like a steal.
5. Is this the end for Paddack in 2019?
Richards starts Monday. Paddack gets the ball Tuesday.
At this point, it would qualify as a surprise if Paddack took the ball again after that. The right-hander has exceeded his 2018 Minor League innings total by 45 2/3 frames. He has had his workload monitored closely this season, and an early shutdown has always seemed likely -- even if the Padres haven’t confirmed it publicly.
Green explained the decision to let Paddack face the Brewers on Tuesday by noting that Paddack would benefit from pitching against a tough offense on the road in a game with playoff implications. Makes sense.
But with Richards back in the fold, the Padres will have a seven-man pitching staff, plus an off-day on Sept. 23. It’s all lining up for Paddack's final start to come on Tuesday.
If so, it would align Richards for three starts before the end of the season. The Padres would view that as a perfect foundation for 2020.
"We look at it as, get him on the mound, make sure he knows going into the offseason that he's ready to go and he doesn't have a question in the back of his mind," Green said. "He's stared down a few Major League lineups, been back on the big stage and he's ready to go [in 2020]."