Porcello went 22-4 with a 3.15 ERA to emerge as the ace of the staff. Price, who signed a seven-year, $217 million contract, recovered nicely after a slow start to the season and entered Sunday looking for his 18th win.
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"It is business as usual," said Porcello. "I figured I'd be pitching one of the first two. Whatever game it is, it's a big game. Whether it's one, two, three, four or five. I'm looking forward to the opportunity."
The Tribe will call on Trevor Bauer to start Game 1 and Corey Kluber for Game 2.
The higher-seeded team for the Cleveland-Boston ALDS had not been determined entering Sunday.
Porcello won his lone start against the Indians, allowing two runs in 5 2/3 innings on May 22. Price beat the Indians on Opening Day, allowing two runs over six innings.
"They have some different guys and some different looks, but the core guys are still the same," said Porcello. "That's a good ballclub. They do a bunch of different things to come at you. We have to prepare for that and be ready to counter."
Clay Buchholz and Eduardo Rodriguez are expected to start Game 3 and Game 4 (if necessary) in some order for Boston.
Porcello struggled through the first half of his first season in Boston and finished 2015 with a 9-15 record and a 4.92 ERA, tied for the highest of his career.
"It tracks back to when he came off the DL last year," said Farrell. "The biggest thing might be just getting comfortable in the surroundings here in Boston. That has been probably the biggest change in all this. You go back to the execution of the sinker, and I know we've talked about this a lot. I know he's evolved as a pitcher, but the ability to execute that pitch as a signature pitch is key for him."
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.