In the span of three games over two days, the Red Sox got the clearest glimpse of how potent the front end of their rotation could be at its absolute best.

Chris Sale, David Price, and Rick Porcello combined to give up just one earned run over 21⅔ innings, putting together mesmerizing performances even as the Sox lineup struggled to put across some runs.

The rotation they envisioned dominating the AL East at the start of the season was starting to hit on all cylinders.

The only question that needed answering coming out of the All-Star break was how Eduardo Rodriguez would return from the dislocated right knee that had kept him on the disabled list since June 1.

If he could quickly regain the form that made him arguably the Sox second-best pitcher in the first half of the season, the team could be comfortable knowing it had a strong rotation anchoring them.

Although he ran into turbulence at times, Rodriguez left the Sox with encouraging signs over his 5⅓ innings of work Monday, holding the Jays to three runs on six hits, striking out eight while walking four.

But a solid effort in Rodriguez’s return went for naught as the Sox offense couldn’t shake out of its recent dry spell enough in a 4-3 loss.

Andrew Benintendi (2 for 3) was the only player in the Sox lineup with multiple hits. Xander Bogaerts and Hanley Ramirez both went 0 for 4. Mookie Betts went 1 for 4 with an RBI single. Dustin Pedroia went 1 for 3 with an RBI double.

Rodriguez got to work quickly, striking out Jose Bautista on three pitches to start the game. He baited the Jays’ slugger with a 93 mile-per-hour fastball above the zone, getting him to check swing for strike three.

The next at-bat, he left a fastball over the middle of the plate and Russell Martin stroked it the other way to right field for a single.

He bounced back and struck out Josh Donaldson a batter later, going back to his fastball on a 2-and-2 count.

But he was using his entire pitch mix early, seemingly searching for something.

He didn’t find it against Justin Smoak, walking him on six pitches, missing with his changeup, fastball, and cutter.

With runners on first and second, and Kendrys Morales at the plate, he tried to go down and in with another fastball, but Morales blasted it off the Monster for a double that plated both runners and gave the Jays an early 2-0 lead.

Things didn’t get much better for Rodriguez in the second.

He tried to go in with his fastball again to Steve Pearce, but didn’t go far enough.

It was dangling closer to the middle of the plate and Pearce launched it into the Monster seats for his eighth homer of the season.

Rodriguez has historically had issues with the Jays. He came in 1-3 with a 6.35 ERA in six career appearances (five starts) against them.

In his final rehab start with Triple A Pawtucket last week, Rodriguez threw 94 pitches, so Sox manager John Farrell didn’t imagine he’d have to set any restrictions on his pitch count.

But with one out in the third, Donaldson worked him for 10 pitches after falling behind 0 and 2. Rodriguez threw every pitch he had at Donaldson except his slider before finally missing with a changeup in the dirt and surrendering the free base.

Rodriguez was sitting on 82 pitches after the fourth inning, which all but ensured the fifth would be his last.

After getting Martin to fly out to center, Rodriguez found himself in a tight spot when he walked Donaldson and gave up a single up the middle to Smoak.

Morales bounced a ground ball deep down the third-base line that could’ve been trouble, but Brock Holt snagged it and fired to second to start a 5-4-3 double play that ended the inning and got Rodriguez out of trouble.

Farrell pushed Rodriguez’s limit, sending him back out for the sixth.

Rodriguez was able to strike out Troy Tulowitzki for the second time, then walked Pearce. With that, his night was over.

Marcus Stroman kept the Sox lineup quiet for the bulk of his 6⅔ innings until the seventh when he made an error covering the bag at first that opened the window for a rally.

With one out and Benintendi at first, Jackie Bradley Jr. chopped a first-pitch fastball down the first-base line. Smoak scooped it, but had trouble getting the ball out of his glove.

Stroman went to cover first, but in the confusion lost track of where he was and didn’t get his foot on the bag. Bradley was safe, and the Sox had runners at first and second with Christian Vazquez coming to the plate.

Vazquez worked a seven-pitch walk to load the bases. Holt followed up by shooting a sacrifice fly to center field to put the Sox on the board and make it 3-1.

That brought up Betts, who laced a single to left field that scored Bradley and cut the Jays lead to 1.

With runners again at first and second, Pedroia jumped on the first pitch Stroman fed him and launched it off the base of the Monster for a double.

Vazquez raced home to score from second. Betts tried to follow in his tracks, blowing through third base coach Brian Butterfield’s stop sign, but he was thrown out on a crisp relay from Kevin Pillar to Tulowitzki to Martin.

Righthander Heath Hembree manned the eight inning.

He ran into trouble quickly when he issued a leadoff walk to Smoak and then a single to Morales. He got a much-needed out when Tulowitzki popped to Pedroia.

But he got into a full-count situation with Pearce and gave up a single on a liner to left field that allowed Smoak to cross the plate and the Jays to reclaim the lead, 4-3.

For the 37th time this season the Sox muster couldn’t muster more than three runs.

Julian Benbow can be reached at jbenbow@globe.com. Julian Benbow can be reached at jbenbow@globe.com.