McLean struck two vital penalties to help the national side reach a major finals for the first time since 1998 – including the winner in the shoot-out against Israel in the Nations League play-off semi-final.
It was widely expected the former St Mirren and Aberdeen man would be included in Clarke’s 26-man squad for the summer’s games which kick off on June 14 against Czech Republic at Hampden.
However the medial collateral ligament injury feared by Canaries boss Daniel Farke has proven severe enough to rule him out for at least 12 weeks and ending his hopes of participation this summer.
Clarke sympathised with the player and admitted: “I’m really disappointed for Kenny. He has been excellent this season for Norwich, playing an important role in winning the Championship and securing their return to the Premier League.
“His performances for the national team during my time in charge have always been to a good level and Kenny is a player I know I can rely on. The composure he demonstrated to score two crucial penalties in the Play-Off matches sums up his temperament and I am confident that will play a big role in his recovery from this setback.
“Ultimately, his long-term fitness is the most important thing right now, but we all wish Kenny a full and speedy recovery and look forward to seeing him get back playing as soon as possible.”