It wasn’t so long ago that Chris Sale was making Red Sox fans worry -- about his health, his velocity and his results.

The left-hander had pretty much put those concerns to rest over his past few starts, but he buried them deep on Tuesday night, with one of the most dominant performances of his accomplished career. Facing the Rockies at Fenway Park, Sale struck out a career-high 17 without issuing a single walk over seven innings.

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Although he did allow two runs -- and ultimately took a no-decision in a 5-4 Boston loss in 11 innings -- Sale still authored an outing worthy of a closer look. Here are 10 facts to know about the latest gem from the Red Sox ace:

• The 17 strikeouts were a career high for Sale, whose previous best was 15. He’d done that three times, most recently on May 11 last year against the Blue Jays.

• Sale’s 17 strikeouts are a record for any pitcher who went no more than seven innings.

• Sale was the first left-handed pitcher to strike out 17 in a game since Johan Santana did it for the Twins against the Rangers on Aug. 19, 2007. He was the third pitcher to do it in Red Sox history, joining Pedro Martinez, Roger Clemens and Bill Monbouquette, with Martinez the most recent to do it, on May 6, 2000, against Tampa Bay.

• This was the 16th time in MLB history that a pitcher struck out at least 17 without walking anybody, and Sale was the 11th to accomplish the feat. He was the first since Max Scherzer, who didn’t have a walk in his 20-strikeout game for the Nationals on May 11, 2016.

• Sale also had no walks when he struck out 14 in his previous start, last Wednesday at Baltimore. That makes him just the second pitcher in baseball history to put together back-to-back outings of at least 14 K's and no walks. The other was Dwight Gooden, who did it on Sept. 12 and 17, 1984, toward the end of his electric National League Rookie of the Year Award season for the Mets.

• The Red Sox elected to remove Sale at the end of the seventh inning, after he’d thrown 108 pitches, even though he had a real shot at 20 strikeouts. No pitcher since at least 2008 had recorded 17 or more strikeouts through the first seven frames -- not even Scherzer, who had 15 when he got to 20 three years ago. In fact, out of the five 20-K games that have been produced, only one featured 17 K's through seven. That was Clemens’ second 20-K game, for the Red Sox on Sept. 18, 1996.

• With his 10th career game of at least 14 strikeouts, Sale passed Curt Schilling and Tom Seaver on the all-time list, and tied Hall of Famer Steve Carlton for seventh place. Of the six pitchers with more, four are also in Cooperstown (Randy Johnson, Nolan Ryan, Martinez and Sandy Koufax). Clemens and Sam McDowell are the others.

Sale also has 68 games with double-digit strikeouts, which ranks 12th. He’s now two behind the Hall of Famer Seaver in that category.

• Sale piled up 24 swinging strikes for the second outing in a row. The only other pitcher with more than one such game this season is Tampa Bay’s Blake Snell.

• Sale now has recorded 17 strikeouts on four-seam fastballs over his past two games, matching his total from his first eight outings of the season.

• Thanks largely to Sale, the Red Sox as a team struck out 21 Rockies through nine innings, before the game went into extras. According to the Elias Sports Bureau, that tied an MLB record originally set by Boston, at Tampa Bay, on Sept. 25, 2016. In that game, the Sox finished with 23 K's in 10 innings. On Tuesday, they finished with 24 in 11 innings, tying the franchise record for strikeouts in a game -- also set against the Rays, in a 15-inning game on Sept. 15, 2017.

Boston finished just two strikeouts shy of the single-game MLB record of 26 strikeouts.