BOSTON -- There was a time not all that long ago that the weekend leading up to the July 31 non-waiver trade deadline would feature the Kansas City Royals selling off assets and hoping to build for the future.

But, for Kansas City, the 2015 World Series champions, that future has suddenly become now -- which is why the Royals were buyers when they picked up three pitchers from the San Diego Padres in a trade.

"Right now everybody's confident, everybody's comfortable, everybody's seeing the ball well and you just ride it," Kansas City manager Ned Yost said after his team won its eighth straight and completed a three-game sweep in Detroit on Wednesday before moving on to Boston for this three-game weekend series beginning Friday. "You don't think about it. You just go out and play hard."

The Royals have outscored their opponents 63-25 during the streak, twice scoring 16 runs against the Tigers. They now trail the first-place and equally hot Cleveland Indians (seven straight wins) by two games as they visit the first-place Red Sox.

When things go well, you get breaks. This weekend, Kansas City gets to face Boston without having to go against Chris Sale.

Sale ended Boston's 2-4 West Coast trip with another dominant win at Seattle on Wednesday. Sale got both of the team's wins on the trip.

"We're watching one of the better years ever pitched by a major league pitcher in the American League, and we're fortunate it's in our uniform," Red Sox manager John Farrell said after Sale's latest gem. "The fact is: We were coming off a four-game losing streak, and, yeah, he stops it right there."

The Red Sox, who will have Eduardo Nunez making his debut at third base Friday, are 6-8 since the All-Star break and lead the New York Yankees by one-half game and the Tampa Bay Rays by three.

The Royals, who optioned pitcher Kevin McCarthy to Triple-A Omaha on Thursday and will make another move Friday, took two out of three from the Red Sox in Kansas City in June.

David Price -- still square in the middle of his off-field controversy, this one involving his berating club broadcaster Dennis Eckersley on a team flight -- will start against a suddenly struggling Jason Vargas in the series opener.

Given Eckersley's popularity and Price's $217 million price tag, it might be in Price's best interests to have a good outing, thus eliminating the possibility of boos.

Price is 5-3 with a 3.82 ERA since returning from the disabled list. His velocity is actually up since coming back from the elbow problem, but he lasted only five innings and allowed six runs (five earned) in his last start, at Anaheim.

He is 4-0 with a 2.13 ERA in eight games (seven starts) lifetime against the Royals. He was 2-0 with a 2.70 ERA against Kansas City with the Red Sox last season.

The Royals, who will start new arrival Trevor Cahill on Saturday night, don't have great numbers against Price.

All-Star Salvador Perez, who left Tuesday's game with rib cage tightness and rested Wednesday, is 5-for-14 with three home runs. Alcides Escobar is 4-for-13.

But Brandon Moss is 1-for-9; Eric Hosmer, who had five hits and drove in six runs Wednesday, is 2-for-16; Mike Moustakas 1-for-7; and Alex Gordon and Lorenzo Cain are each 4-for-17.

Asked about Perez on Wednesday, Yost said: "This will give him two days off. Could he have started tonight? Yeah. In fact, he fought me about it. But it's better to take the two days off and be ready for Boston on Friday. He'll be back then."

Vargas, an All-Star who is 12-4 with a 3.08 ERA, is winless in his last three starts and has a 9.95 ERA in July -- after going 6-0 with a 1.98 ERA in June.

Vargas is 2-3 with a 3.74 ERA in seven starts against the Red Sox but is 1-1 with a 6.23 ERA in two games Fenway Park, where he hasn't pitched since 2012 (with Seattle).

Mookie Betts and Xander Bogaerts are each 2-for-3 against him, while Chris Young is 2-for-13 and Mitch Moreland 3-for-17.

Nunez is 6-for-21 against Vargas.