Six tries in seven starts is some record, and surely his performance against Italy signalled the start of a long run at national level for the 22-year-old Edinburgh threequarter.
Instead, Kinghorn finds himself dropped to the bench for the visit of Ireland tomorrow, with Gregor Hastings sticking with his plan to return Sean Maitland to the starting line-up against the champions.
While Kinghorn may have all the exuberance of youth, Maitland’s experience with Saracens and the Lions means he gets the nod having recovered from a hamstring injury.
“We were always hoping Sean would get back for this game,” said head coach Gregor Townsend.
“Sean would have been starting against Italy with Tommy Seymour if he’d been fit.
“Blair’s performance did mean we had an extended discussion, but we believe Tommy and Sean are best equipped for this game.
“But nothing should be taken away from Blair’s performance. He was quiet [when told]. He’ll be disappointed, I know.”
Townsend also has key second-rower Jonny Gray back from injury while hooker Fraser Brown is named on the bench.
But with WP Nel and Sam Skinner now ruled out with knocks picked up last weekend, Townsend will rely on his tried-and-trusted troops more than ever if they are to repeat their 2017 Murrayfield triumph.
Ireland coach Joe Schmidt’s hand has been forced the opposite way, with Robbie Henshaw’s dead leg leading to Chris Farrell making his first test start in almost a year.
Rob Kearney has returned at full-back after the experiment of moving Henshaw to 15 to face England failed amid Ireland’s heavy defeat in Dublin.
Quinn Roux will partner James Ryan at lock, with Devin Toner having joined Iain Henderson and Tadhg Beirne on the injury list.
Henshaw’s injury blow, coupled with Garry Ringrose’s hamstring problem, has opened the door for Munster’s battering-ram centre Farrell to win his fourth cap having struggled with a string of knee injuries since his last Test appearance, a man-of-the-match showing in Ireland’s victory over Wales last February.
SCOTLAND: Hogg; Seymour, Jones, Johnson, Maitland; Russell, Laidlaw (capt); Dell, McInally, Berghan, Gilchrist, Gray, Wilson, Ritchie, Strauss. Replacements: Brown, Bhati, Rae, Toolis, Harley, Price, Horne, Kinghorn.
IRELAND: Kearney; Earls, Farrell, Aki, Stockdale; Sexton, Murray; Healy, Best (capt), Furlong, Ryan, Roux, O’Mahony, O’Brien, Conan. Replacements: Cronin, Kilcoyne, Porter, Dillane, Van Der Flier, Cooney, Carbery, Larmour.