The accident happened Saturday while the AL East-leading Red Sox warmed up at Yankee Stadium.
And in the ninth, Hicks' throw from left field - completing a crucial double play - might have saved Aroldis Chapman from a critical blown save.
"He's a game changer on both sides of the ball", Gardner said of Hicks.
Said manager Joe Girardi: "It was a pretty big loss for us".
The Red Sox were supposed to be the team making a fool of the Yankees on Friday night.
Jameson Taillon pitched into the seventh inning and Pittsburgh scored four unearned runs in the third inning of a victory over Toronto.
Indeed, the Red Sox appeared to have matters well in hand when they turned over a three-run lead to newly acquired setup man Addison Reed in the eighth inning.
Then Hicks, in his second game back from a six-week stint on the disabled list, lofted a full-count pitch from Reed high down the right-field line. "These are extremely important games", Girardi said. Hicks had never previously faced Reed and was just "looking to get a ball up and try to get a hit in that situation". Aaron Hicks got the Yankees going with a two-run homer before Didi Gregorius and Todd Frazier added RBI singles to put NY ahead 4-3.
Four pitches later, Frazier blooped Kelly's 100 miles per hour fastball in front of left fielder Andrew Beintendi as Judge scored. A sacrifice fly by Ronald Torreyes made it 5-3 and completed a rally that few saw coming.
Allowing fans from Yawkey Way to Babe Ruth Plaza an opportunity to gorge on "The Rivalry" is one thing. Boston has run into 64 outs on the bases, 15 more than any other team in the American League.
Severino is 1-3 with a 3.45 ERA against the Red Sox in six career games (five starts).
Kyle Schwarber homered in his first game in Chase Field since being badly injured there last season, Alex Avila followed him with another homer and Kris Bryant reached base five straight times to lead Chicago past Arizona.
The lefty recently lost his rotation spot and was sent to the minors when the Yankees traded for starters Sonny Gray and Jaime Garcia. Andrew Benintendi's two-out, solo homer made it 3-0 in the fifth.
Atlanta Braves starter Mike Foltynewicz did not even make it out of the third against the St Louis Cardinals, giving up seven hits and six earned runs while walking four in 2 2/3 innings.
Garcia gave up a first-inning, two-run homer to Hanley Ramirez with two out. He still allowed seven hits, walked three and gave up a handful of loud outs, but he kept the Yankees within range with a veteran's guile, leaving the bases loaded in the third and stranding runners in scoring position in the second and the fifth. Rodriguez had seven Ks.
In a corresponding move, the Yankees recalled left-handed pitcher Jordan Montgomery from Triple-A Scranton/Wilkes-Barre to start Sunday opposite Boston's Chris Sale.