Perth, Feb 2 (IANS): England One-Day International (ODI) captain Eoin Morgan "can't put his finger" on why his side collapsed in the tri-series final against Australia Sunday, but Monday said he was certain it had nothing to do with returning Australian spearhead Mitchell Johnson.

Chasing 279 to win the tri-series final, Morgan's men collapsed to be 98 for seven in the 25th over, with Johnson tearing through England's top order to finish with three for 27 from seven overs.

It was Johnson's first game back since the Boxing Day Test against India in Melbourne and the left-arm speedster showed no sign of rust as he tormented his favourite prey on his adopted home turf.

Johnson removed James Taylor with his seventh ball of the day to a sharp catch by Glenn Maxwell at backward point before ripping through Moeen Ali and Morgan with consecutive balls next over, with the captain leaving a ball that cannoned into off-stump.

But Morgan said, it "could have been anybody bowling" and specifically it wasn't Johnson's spell that changed the game and reminded the tourists of last summer's horrors.

"Absolutely not, I don't think he swung it," said Morgan on Johnson's opening spell.

"The two guys up front bowled well, swung it a little bit, but again we must have put ourselves under pressure.

"I don't know why we performed like this. Our biggest worry was the pitch. We didn't know what the pitch was going to be like and it turned out to be better than we thought."