The Red Sox have 20 games remaining in the regular season and the mystics and statistics suggest they will surely make the playoffs. That makes the October readiness of Chris Sale of paramount importance.

Sale has yet to pitch in a postseason game and it falls on manager John Farrell to make sure he is not worn out once he gets there.

That process played out at Fenway Park on Saturday night. Sale, who was pitching on an extra day of rest, pitched a stress-free six innings in a 9-0 victory against the Tampa Bay Rays.

At 81-61, the Red Sox are 20 games over .500 for the second time this season. They have won four straight and maintained a 4½-game lead on the Yankees in the American League East.

The Rays are essentially out of wild-card contention, having lost five of seven.

Dustin Pedroia reached base four times and scored four runs. Andrew Benintendi was 3 for 5 with a double and three RBIs.

The Sox have scored 18 runs on 27 hits the last two nights. They will try for the series sweep on Sunday afternoon with Rick Porcello on the mound.

Sale leads the American League in innings with 195⅔ but is being used cautiously down the stretch, the Sox taking advantage of days off in the schedule to give him breaks whenever possible.

Sale (16-7) took full advantage of the run support, going six innings and striking out eight with one walk as he challenged the Rays every chance he could. He allowed six hits, all singles.

Sale dropped his earned run average to 2.76. He will get another extra day of rest before his next start on Friday at Tampa Bay.

Depending on whether the Sox need him in the final series of the season, Sale has three or four starts remaining. He has 278 strikeouts, 35 away from tying the team record of 313 set by Pedro Martinez in 1999.

The Sox sent 16 batters to the plate in the first two innings and eight scored. Tampa Bay starter Matt Andriese was charged with all eight runs, six of them earned.

Eduardo Nunez started the first inning with a single. Pedroia then homered to left, the ball just clearing the wall. It was his first extra-base hit in 18 at-bats since coming off the disabled list.

With one out, Mookie Betts created a run with his speed.

He singled, stole second and went to third on a throwing error by catcher Wilson Ramos. The Rays pulled the infield in for Mitch Moreland and he grounded to shortstop Adeiny Hechavarria.

Betts was off on contact and Hechvarria took the out at first base knowing he had no play at the plate.

The Sox scored five runs in the second, all with two outs.

With Rafael Devers on first, Nunez reached on an infield single then left the game with a bruised right knee.

Pedroia then walked to load the bases. Benintendi lined a double off the wall in left and two runs scored. The Rays intentionally walked Betts to get to Moreland and he slammed a two-run single off the wall.

That was the end of the game for Andriese, who has given up 11 earned runs over 9⅔ innings since coming off the disabled list on Aug. 28.

The Sox added another run, Betts scoring on a throwing error by third baseman Evan Longoria.

Singles by Xander Bogaerts, Pedroia, and Benintendi gave the Sox another run in the third inning.

Bogaerts, who replaced Nunez, was 2 for 3. The Sox got four hits and three runs from the leadoff spot.

Peter Abraham can be reached at pabraham@globe.com. Follow him on Twitter @PeteAbe.