"We played well in the first half and we had three of four chances but Celtic took advantage of an offside position to score their first goal," the former River Plate coach said. "I didn't see the sending off but it really changed the course of the game."
Villarreal had already qualified for the second stage of the tournament and with Manchester United drawing with Aalborg they passed up the opportunity to top the group. Pellegrini was surprisingly unconcerned about his teams missed opportunity. "I don't feel we have lost anything because we have qualified."
Celtic Manager Gordon Strachan took the opportunity to reflect on a less than glorious Euro campaign that saw his side only manage to collect 5 points out of a possible 18.
He said: "We had a penalty at home against Aalborg and (if we score) we win the game and that's three points.
"We did enough in Aalborg to win the game; everybody in this room whom I met has said we deserved to win. We had a smashing performance against Villarreal away and we were six minutes away from beating Manchester United here although we obviously had our backs to the wall.
"If you look at that then you can count up a few points that went missing. But the longer we stay as a group the better it is for everybody. If we stay together and don't have to sell anybody, then that will be smashing."
Yours in Celtic
Clydebuilt