Looking to improve to 3-0 this month, the right-hander tries to help the surging Angels hand the Boston Red Sox a fourth consecutive defeat Wednesday night at Fenway Park.
Richards (13-4, 2.53 ERA) was dominant during a nine-start stretch in which he went 7-0 with a 1.25 ERA, but followed by posting a 5.54 ERA to lose the final two of July.
With a new month came renewed success for Richards, who is 2-0 with a 1.19 ERA in three August outings. He allowed two runs and struck out seven without a walk in 7 1-3 innings of a 5-4 victory at Texas on Friday.
"He's coming into his own," Angels catcher Chris Iannetta said.
"We're just seeing him mature. He's got great stuff, and he's starting to command it more.''
Richards' August success includes his only previous start versus Boston (56-69). He gave up three runs - one earned - and three hits in 6 1-3 innings of a 5-4, 19-inning victory Aug. 9.
Clay Buchholz (5-7, 5.79) opposed Richards in that game and allowed three runs while striking out eight in eight innings. The right-hander followed that outing by giving up two and fanning nine in seven innings of a 5-3, 10-inning home defeat to Houston on Friday.
Prior to those two starts, Buchholz endured a four-start stretch where he went 1-2 with a 9.00 ERA.
He'll try to help the Red Sox end their current struggles and cool off the Angels (74-50), who have won two straight and six of seven following Tuesday's 4-3 victory.
"It's a great clubhouse to be in right now. This team is on a roll," said Brennan Boesch, who scored the go-ahead run in the ninth.
Calhoun, who also leaped at the low right-field fence to take a three-run homer away from Brock Holt in the second inning, is batting .391 with nine RBIs in the last 10 games.
Trout is hitting .444 with six RBIs in eight career games at Fenway.
After sitting the previous two contests, Los Angeles' Josh Hamilton was 0 for 3 and hit by a pitch Tuesday, leaving him 5 for 41 in his last 11 games.
''He's going to have to figure it out,'' manager Mike Scioscia said. ''He's not going to figure it out sitting.''
The breakout might not come Wednesday considering Hamilton is 2 for 22 with two doubles versus Buchholz. That .091 average is Hamilton's second worst among the 28 pitchers he has faced at least 20 times.
Trout is 6 for 13 with two homers against Buchholz while Pujols is 5 for 12 with a pair of doubles.
Boston's David Ortiz went 1 for 2 with a double versus Richards this month. Ortiz, who hit his 29th home run Tuesday, is batting .455 with three homers and eight RBIs in the last six contests.
Yoenis Cespedes is batting .231 in 16 games since Boston acquired him from Oakland at the trade deadline, but is 4 for 10 with two doubles against Richards this season.