CINCINNATI -- Rick Porcello wasn't thrilled to be removed from Friday night's game after 57 pitches and four innings, with the Boston Red Sox leading by one run. And as recently as 10 days ago, he wouldn't have been, at least according to manager John Farrell.

But that was before David Price took up residence in the bullpen.

If Price's first regular-season relief appearance in seven years -- a six-up, six-down domination of the Tampa Bay Rays on Sunday -- didn't convert all the non-believers into thinking he can be an October game-changer for the Red Sox, the performance he turned in here Friday night really ought to do the trick. Price took over for Porcello, tossed 2⅔ scoreless innings and picked up the win in a 5-4 victory over the Cincinnati Reds.

"I know Rick did not want to come of that game, and I fully respect that," Farrell said after the Red Sox increased their American League East lead to four games over the New York Yankees with nine to play, lowering their magic number to clinch the division title to six. "I just felt like, with the left-hander in David going up against the heat of that order, it was the move to make."

Porcello and the other starting pitchers might want to get used to it. The Red Sox still aren't sure how frequently Price will be able to pitch in his new relief role. Against the Reds, he was working on four days' rest, the typical recovery time for a starter.

But Farrell's aggressive usage of Price, particularly against a lefty-heavy lineup, might be a preview of things to come. Rather than subject Porcello to a third time through the Reds' order, Farrell went to Price in the middle innings to bridge the gap to setup man Addison Reed and eventually closer Craig Kimbrel, a formula the Red Sox hope to repeat frequently during the playoffs.

And once again, Price delivered. He shelved his curveball against Reds hitters who like to swing early in the count, cranked up his fastball to 95 mph, sprinkled in the occasional changeup and recorded eight outs.

Price was so effective that Farrell even let him hit for himself in the sixth inning. He came through with his bat, too, blooping a leadoff single into left field. It was his first hit since 2010 and only his third in 48 career at-bats, and it brought a rare smile to the face of a pitcher who has scowled his way through an injury-riddled season in which he has often sparred with the media.

"I liked hitting way more," Price said. "That was cool. I was due."

But the Red Sox are paying Price $31 million this season because of the impact he can make with his left arm. Two trips to the disabled list, including a seven-week stint after soreness returned to his elbow and triceps following a July 22 start in Anaheim, California, have left the 32-year-old without enough time to rebuild the arm strength to start in the postseason.

That doesn't mean the Red Sox can't use him out of the bullpen in the same way the Cleveland Indians use Andrew Miller, specifically to get outs in the middle of a game against the heart of an opponent's lineup.

"He's healthy and that's the beauty of all this," Farrell said. "All the work that he's put in to get back to this point, and then still, I don't want to say marvel at it, but the way he comes out and throws strikes -- and quality strikes. We're talking five innings in the past two months, and it's impressive to see the way he commands the baseball."

Price has already made an impact on the AL East race. The Yankees are 14-6 in their past 20 games, but the Red Sox have been able to keep them at arm's length by winning 12 of their past 15. Price played a large role in two of those victories.

"We don't care what the Yankees do. Just go play our game," Price said. "We're in first place for a long time now. Ball’s in our court. If we win, we’re fine."

Porcello gave up a grand slam to Scooter Gennett in the first inning, but he appeared to be settling down by the fourth inning. He worked around a one-out walk to Gennett in the third inning and a hit by pitch to open the fourth, and when Rafael Devers homered for the first time in 116 plate appearances, Porcello had a 5-4 lead.

Farrell admitted it's "not likely" that he would've pulled Porcello if Price hadn't been available, especially against lefty-hitting Joey Votto and Gennett in the fifth inning. But if Porcello or fellow starters Drew Pomeranz, Doug Fister and Eduardo Rodriguez don't think Farrell won't do it again, particularly in the postseason, they would be kidding themselves.

"That's the reason you make the move, to have someone throwing the ball as well as David did down in Tampa," Farrell said. "Hopefully that was going to be the case tonight. It worked out."

So far, the Price experiment is working out as well as the Red Sox could have hoped.