Former defender Jeremie Frimpong insists Celtic's failed 10 In A Row bid is "normal" because they "can't win everything".
The former Manchester City youth moved to the Bayer Leverkusen in January for a fee of £11.5million with the club well off the pace in the Premiership title race.
St Johnstone's League Cup win brings to an end the Hoops' dominance of silverware, with Rangers looking destined to reclaim the Premiership trophy for the first time in a decade.
This has led to boss Neil Lennon resigning his post as the club look to spark a significant rebuild with incoming chief executive Dominic McKay arriving with a new boss.
Frimpong, speaking at a press conference for the Bundesliga side, believes there has been an overreaction to the sides struggles this term and glory periods always have to come to an end.
He said: “I think in football, obviously Celtic in previous years they always win, but there was always going to be a point where they can’t win everything, so there was always going to have to be a time where they have to lose.
“So the criticism Neil Lennon was getting was a bit over the top, because in football, it’s normal.
"I feel like at Celtic, the fans they were so used to winning that when they started going down they didn’t know how to feel about it, but it’s normal to feel like that.”
During his time at Celtic Park, the full-back lifted two Premiership titles alongside two League Cup and Betfred Cup victories.
