ST. PETERSBURG -- The visions the Red Sox had of a satisfying sweep at Tropicana Field started to vanish by the middle innings, and dissipated in a sea of confusion and delays in the late innings in Wednesday afternoon’s 3-2 loss to the Rays.

With two outs in the top of the eighth, Red Sox manager Alex Cora informed the umpires he was playing the remainder of the game under protest.

The controversy stemmed from Rays manager Kevin Cash moving lefty Adam Kolarek from the mound to first base after getting the first out of the inning, and then bringing him back to the mound to pitch against Rafael Devers with two outs. The confusion was over lineup placement.

• Box score

According to crew chief Angel Hernandez, Cash didn’t specify where Kolarek would go in the lineup when he initially put him at first base. Hernandez told a pool reporter that when the manager doesn’t specify, the rulebook states that the lineup placement is then up to the home-plate umpire.

• Who's on first? Rays' subs lead to Sox's protest

Hernandez placed Kolarek into the third spot in the batting order -- which was occupied by designated hitter Austin Meadows. And Nate Lowe, who came on to play first base when Kolarek returned to the mound, was in the ninth spot.

“They did the pitcher moving to another position and we felt that they made some illegal substitutions,” said Cora. “It was a mess at one point. I wasn’t able to keep up with Angel. We protested the game. Let’s see where it goes.”

No matter where the protest goes, the Red Sox came away from these three games at Tropicana Field feeling good about what they accomplished.

In the start of a 14-game stretch in which the Sox play only the Rays and Yankees, they won the first two in St. Petersburg before being narrowly defeated at the hands of nasty Tampa Bay righty Charlie Morton in the finale.

“We won the first two games, lost the 3-2 game today,” said lefty David Price. “That’s the team that’s right there with us in the standings. For us to play good baseball after a tough series in Baltimore was good.”

Morton (12-3, 2.60 ERA) proved why he is one of the best pitchers in the Majors, holding the Sox to five hits and two runs over seven innings in which he walked none and struck out 11.

You don’t have to tell Cora how good Morton can be when he is at the top of his game. Cora was the bench coach for the Astros when Morton put the team on his back en route to victory in Game 7 of the 2017 World Series.

“Charlie was good,” sad Cora. “Good fastball up in the zone. Good breaking ball later in the game.”

Price (7-4, 3.66 ERA) held up his end of the duel for the most part. The lefty was staked to an early 2-0 lead in the third inning when Devers perfectly placed a two-run single through the shift and just out of the reach of third baseman Matt Duffy.

Two mistakes -- a solo homer to Tommy Pham in the fourth and a go-ahead RBI double to Guillermo Heredia in the fifth -- proved to be the difference in the game.

Given who he was facing, Price knew those mistakes were more costly than they would be on most days with the powerful Boston lineup behind him.

“Absolutely. The way he’s thrown the baseball all season long for these guys ... that’s very impressive,” Price said. “Going against him, you get staked to an early 2-0 lead, to give that up and give up those three runs was tough.”

Looking at the big picture, Price displayed improvement from the slide over his previous three starts, when he lasted five innings or fewer each time. He went six in this one and struck out eight, giving the Red Sox four straight games in which the starting pitcher went at least six innings.

For weeks, Cora has been saying that his team will go as far as the rotation takes it. At last, the starting rotation seems to be on the upswing again.

“We’ve been saying all along, we need these guys to not carry the team but give us a chance to win,” said Cora. “That’s the fourth start in a row that they go six-plus. If we do that on a consistent basis, our chances of getting into that streak, the one we’ve been talking about from the get-go, will improve.”

With a week to go before the Trade Deadline, there will be even more scrutiny than usual for the defending World Series champions, who have been trying all season to get back to the team they envision themselves as.

At 56-47, the Sox travel home trailing the Yankees by 10 1/2 games in the American League East and the Athletics by two games in the race for the second AL Wild Card spot. No matter what the divisional standings show, Fenway Park should be rocking for the next four days.

“Very big,” said Price. “That’s another team in front of us in the standings. It’s crunch time for us right now. We all understand that in this clubhouse. Just go out and win tomorrow and play good baseball.”