City would have won the UEFA cup in 1979 if Allison had played Deyna in the quarter final against Borussia Mönchengladbach.
Malcolm Allison gave an 18 year old Nicky Reid his debut in place of Deyna in the game at Maine Road that finished 1-1. Deyna was on the bench I think back in the days of only 1 sub. He didn't come on. City lost 3-1 in Germany and Mönchengladbach went on to win the cup.
Kazi Deyna was killed in a car crash in California in the early 90's IIRC. He could play football.