The four home runs allowed represented a career-high for Porcello in his 244th Major League start. The 4 1/3 innings marked his shortest regular-season performance since July 29, 2015, ending a streak of 43 starts of five innings or more.
Porcello had delivered 15 consecutive quality starts entering Friday, the longest active streak in the Majors. Pedro Martinez (19 straight QS from Aug. 19, 1999-June 20, 2000) is the only Red Sox pitcher in the last 100 years who had a longer streak.
If anyone has earned a mulligan after such a long run of consistency, it is Porcello.
The only reason it raises some concern is that it came on the heels of the righty allowing 11 hits to the Tigers in his last start, though he limited the damage (3 ER over 6 innings) in that one.
"You can live with singles. I don't think it's so much the number of hits. I'm attacking guys with the fastball," said Porcello. "It's just about location. That's it. I've got to get better with my sinker and four-seamer command and using those two fastballs. That's really the bottom line. There's no secret to it. It's pretty simple. Execute the ball better."
The pitch Porcello made to Logan Morrison for a grand slam was the definition of mislocation. The 2-0 changeup was belt high, and in the middle of the plate.
"I felt like he didn't command his offspeed pitches the way he usually does, nor his heater," said Morrison. "He didn't really have a feel for the inside pitch to lefties. He was leaving it middle when he was coming in. If it wasn't middle it was well off."
Porcello logged a career-high of 223 innings last season, but it's too early to suggest that work load is taking a residual toll. Velocity readings on the 4-seamer and 2-seamer are nearly identical to what they were at this time last year.
"Yeah, I feel fine," Porcello said. "Mechanically I'm pretty much the same. It's just pinpointing the fastball. I'm not locating it well enough to get in advantage counts and it's causing me to leave pitches over the plate when I fall behind."
In three starts, Porcello is 1-1 with a 7.56 ERA. But this early in the year, that ERA could shoot way back down after one strong outing.
"Probably comes back to location," said Red Sox manager John Farrell. "Not physical. Not a lingering effect of innings a year ago, nothing like that. He's strong physically, [side] work has been consistent, it's a matter of in-game location."
Porcello will get a chance to wash the bitter taste of this one out of his mouth when he pitches against the Blue Jays in Toronto.
"It's just making pitches," Porcello said. "That's it. I've been in this situation before. Everybody gets roughed up a little bit. Just take a deep breath, slow the game down, make some pitches."
There was no concern in the clubhouse about Porcello.
"I don't even worry about Rick," Red Sox shortstop Xander Bogaerts said. "He's a good pitcher, a great pitcher, that's why he was best in the American League last year. He'll definitely turn it around and have plenty of great games for us this year."
Ian Browne has covered the Red Sox for MLB.com since 2002. Follow him on Twitter @IanMBrowne and Facebook. This story was not subject to the approval of Major League Baseball or its clubs.