The Toronto pitcher gave up three more homers Tuesday as the Washington Nationals defeated the Blue Jays 4-2.
Bryce Harper, Danny Espinosa and Jhonatan Solano went deep to account for all four runs that Alvarez gave up over seven innings.
"He's missed in the middle of the plate," Blue Jays manager John Farrell said. "When he's missed on the plate, he hasn't gotten away with a mistake."
Alvarez (3-6) has allowed 16 home runs, tied for second most in the American League, in 13 starts this season.
Alvarez feels that he has been pitching well for the most part.
"I don't feel I need to change anything," he said. "Just keep the ball down."
Nationals starter Chien-Ming Wang (2-2) needed 95 pitches to work through five innings, allowing four hits — including a two-run homer by Jose Bautista — five walks and two runs while striking out five.
He threw only 48 strikes but it was enough to earn the win.
Tyler Clippard pitched the ninth for his ninth save.
It was the fifth victory in a row for the National League East-leading Nationals (37-23), all against American League East teams. They swept the Boston Red Sox in a three-game series at Fenway Park before going to Toronto.
It was the fifth loss in the past six games for the Blue Jays (31-31), who will try to salvage one win from the three-game interleague series on Wednesday afternoon.
The Nationals are making up for some difficult seasons.
"I don't know about the history and I don't care about the history too much," Nationals manager Davey Johnson said. "This is a whole new group of guys and they've been playing very well. The pitching has been outstanding and we're getting key hits."
Alvarez allowed nine hits and no walks while striking out three. Part of the problem for Alvarez is that his sinker isn't always sinking.
"The sinker particularly to left-handers, it's got more of a riding action and lateral movement rather than the downward sink than we've normally seen from him against lefties," Farrell said. "It's the inconsistency of the depth of the sinker, which is his best pitch. And if he’s up in the zone a little bit without that late hard sinking action we've seen what's taking place."
The 19-year-old Harper, who had three hits in Monday’s 6-3 Nationals victory, connected for three more on Tuesday. He powered his seventh homer of the season, an impressive shot off Windows restaurant in centre field, with two out in the third to produce the first run of the game.
"I don't really hit big home runs," Harper said. "It's usually just line drives that get going. That was a pretty good one tonight. I was going up there swinging out of my shoes first pitch, I already made my mind up in the on deck circle. I didn't swing first pitch all series yet so I was going up there for sure swinging first pitch, I didn't care if it was a curveball (that went) 54 feet."
The Nationals added two runs on Espinosa's sixth homer of the season with two out in the fourth. It scored Adam LaRoche who led off with a double.
Bautista hit his 18th homer of the season to cut the lead to 3-2 in the fifth. It scored Brett Lawrie who led off with a walk and reached second base when Espinosa did not cleanly field a sharply hit ball by Colby Rasmus that resulted in out at first instead of a double play.
The Nationals came back with another homer in the seventh, the first of Solano's major-league career with two out to bump their lead to two runs. It also was the first major-league run batted in for the Colombian in the catcher’s fourth game after being promoted from triple-A Syracuse on May 28.
Notes: Attendance at Rogers Centre was 22,538....Blue Jays pitcher Brandon Morrow will be put on the disabled list on Wednesday after coming out of his start in the first inning on Monday with a strained left oblique . Farrell said there is no time-line for his possible return...Yan Gomes was returned to Class AAA Las Vegas before Tuesday’s game. ...Left-handers Aaron Laffey and Evan Crawford were called up after Monday’s 6-3 loss to Washington and Chad Beck was demoted. ...Bautista walked in his first two plate appearances on Tuesday and has reached base in 13 consecutive games and in 18 of his past 19 games. ....Toronto will start Kyle Drabek (4-6, 4.43 earned-run average in Wednesday afternoon’s series finale against Stephen Strasburg (7-1, 2.41 ERA).