Both usually prolific offenses are without their premier threats -- David Ortiz for the Sox and Jose Bautista for the Jays -- putting pitching at that much more of a premium.
Many of the arms in Boston's rotation have been up and down, but things have started to take a turn for the better since the All-Star break.
The Sox have gotten four quality starts since the Midsummer Classic, winning all four of those contests.
"I think we have quality guys who are starting who really haven't gone on a continuous roll together," Red Sox manager Bobby Valentine said. "Part of that is because of some injuries and the things that happened in the first part of the season. But I think now they're healthy and they're feeling good about themselves. I think that's a good way to get on a roll."
Already on a roll is Saturday starter Aaron Cook, who has allowed four runs (three earned) in 22 innings over his last three starts.
Cook has an unusual style, with only two walks and two strikeouts in 29 2/3 innings this season. He didn't record a walk or a strikeout in his last outing, allowing only one unearned run on five hits in seven innings against the White Sox. The outing was Cook's second in five starts without any walks or strikeouts.
"I was able to get in a good rhythm and pound the bottom of the strike zone with my sinker," Cook said. "Another game with no strikeouts, but my defense played great behind me."
The Blue Jays' rotation has also been seeking consistency, mostly due to injuries.
Saturday starter Carlos Villanueva opened the year in the bullpen before moving into the rotation on June 29.
In two July starts, Villanueva has thrown 12 scoreless innings, allowing seven hits against 15 strikeouts.
Villanueva battled control issues his last time out, walking five batters, but always managed to pitch his way out of jams en route to six scoreless frames against Cleveland.
"Carlos was at his best when he had men on," Blue Jays manager John Farrell said. "They had the start of multiple innings with guys on base, but, repeatedly, he made a number of big pitches to squelch any threat."
Toronto: Blue Jays add pitching depth via trade
The Blue Jays acquired left-handed starter J.A. Happ and relievers Brandon Lyon and David Carpenter in a 10-player swap with the Astros on Friday morning to bolster a pitching staff that has been decimated by injuries.
Happ and Lyon will both work out of the bullpen, while Carpenter is reporting to Triple-A Las Vegas. The Jays gave up Ben Francisco, Francisco Cordero and a series of prospects in the deal. They also recalled outfielder Travis Snider from Las Vegas.
Snider started in left field on Friday against Boston, finishing 1-for-3 with a double and a walk.
Brett Lawrie sat out Friday's game after suffering a contusion on his right calf when he dove into the camera well to catch a popup on Wednesday at Yankee Stadium.
The Blue Jays' third baseman said he was feeling better on Friday after icing the calf on Thursday, speculating that he might be able to return on Saturday.
Lawrie is 0-for-14 in his last five games.
Boston: Saltalamacchia expected back on Saturday
After being held out of the Red Sox starting lineup for three consecutive games to rest and try to break from his slump, catcher Jarrod Saltalamacchia is expected to start on Saturday.
Saltalamacchia leads Major League catchers with 17 home runs, but he is hitless in his last 14 at-bats and has been stuck in a 1-for-25 slump during his last eight games.
He entered as a pinch-hitter in the ninth inning on Friday against Toronto and struck out swinging to end the game.
Toronto evened its season series against Boston, 5-5, with Friday's win.
Kelly Johnson, mired in a 1-for-17 slump, is 1-for-14 in his career against Cook.
Adrian Gonzalez is 2-for-12 in his career against Villanueva.