Playing his first game in over three months following a foot injury, Keane only managed to show the occasional touch of class as his teammates were swamped by the energy and enthusiasm of lowly Clyde.
Afterwards, he made no comment on the display, however an embarrassed Celtic manager Gordon Strachan admitted that the result was “worse” than the 5-0 Champions League defeat by Artmedia Bratislava earlier in the season.
Trailing by 2-0 at the interval, Celtic also had to ponder the fact that Clyde had one perfectly legitimate goal disallowed by the referee and that their goalkeeper Boruc had saved a penalty.
With 34-year-old Keane a peripheral figure, Celtic managed to reduce the deficit, but they never looked like drawing level.
“In any game of football, if you don’t create chances, have any shots or seem unable to pass the ball back to your keeper, then your tactics are not working,” said Strachan.
“I’m disappointed and saddened, but not humiliated. I’ve been humiliated a few times in my life, but not on the football field.”