In his first start since being named the Angels' fifth starter, Richards (3-2) gave up the four runs in five innings, allowing five hits and three walks while striking out two. It was the first time this season the Angels (53-45) have lost one of Richards' home starts.
In the first and second innings this season, Richards has given up 14 runs in 16 innings, and opponents are hitting .361 against him with four home runs and 10 walks. But after the first two innings, the righty has an ERA of 1.95.
Control issues continue to plague Richards, however, as he has allowed 26 walks in his eight starts this season.
"I gave up a couple hits, walked some guys, fell behind in counts on some guys," Richards said. "I've got to be better at pounding the zone and getting strike one."
The Royals (41-55) got two runs in the first inning on a two-run homer from Lorenzo Cain that scored Alex Gordon, who doubled to start the game, and two runs in the second inning on an RBI single from Gordon and an RBI forceout from Alcides Escobar.
After his early struggles, Richards settled down like he usually does in the following three innings to retire 10 out of the final 11 batters he faced, allowing just a walk.
"He's still a power arm trying to harness some stuff, and when he does, you see it plays," Angels manager Mike Scioscia said. "He just let some things get away from him early and did not have command of the count. When he's not commanding counts, it's tough for him to bring his secondary pitches in to gain the part of the zone."
After Richards' departure, Jerome Williams, whose spot Richards took in the rotation, came in to throw four scoreless innings of relief.
In his last five outings before Tuesday, Williams gave up 24 earned runs in 28 2/3 innings. He allowed five earned runs in each start but one, raising his ERA from 3.68 to 4.85, essentially losing him his spot in the rotation.
Though it was a poor start against the Tigers from Williams and a fine start from Richards against Detroit that earned the two pitchers their current jobs, Tuesday's outings don't necessarily translate into a flip-flopping of positions just yet.
With the back end of the rotation as big a question mark as it is, Scioscia said he'll continue to evaluate his staff and look for the guy who takes the reins on a more consistent basis. He just hasn't seen it yet.
"I don't think it's going to be a ham-and-egg thing to say, 'You're throwing the ball well, come take the ball,'" Scioscia said. "There are some things in Jerome's game that came out that are exciting. There's some stuff that Garrett's been doing, things that we need. I think it's very clear what's going to happen -- it's really who's going to step up and get it done."
While it took two innings for Richards to settle into the game, Royals starter Will Smith took only one to find his groove and control the Angels.
After allowing a run on two hits and a walk in that first inning, Smith (2-3) shut down the Anaheim offense through the next six innings, allowing no hits while stranding two baserunners.
Before his seven innings of two-hit, one-run ball on Tuesday, Smith had given up 18 runs on 26 hits in 20 1/3 innings in his previous four starts coming into the game. The Angels were 12-1 with a .342 average in their last 13 games against left-handed starters before facing Smith.
"Something just clicked," Smith said. "Some nights are like that. You struggle through the first innings with fastball command, something clicks and it's there. The first three innings I had no fastball command, and after that it showed up, which was nice."