Rooney was shown a red card in the 62nd minute for a clash with Ricardo Carvalho.
"It was violent play and therefore he got a red card," Argentine referee Horacio Elizondo told Tuesday's edition of the Times.
Portugal's Ronaldo rushed 40 metres to the referee, apparently to demand a card for Rooney who had battled his way through two players and trod on Carvalho's groin as he tried to disentangle himself.
Rooney pushed Ronaldo, his Manchester United team mate, who was captured on TV cameras winking at his bench as the England forward walked off the pitch having been dismissed.
"People can say what they want but this had absolutely no influence," Elizondo said.
"In general I don't pay much attention to that sort of thing because I don't care about the pressure on my shoulders during a match.
CLEAR RED
"For me it was a clear red card, so I didn't react to the Portuguese players. There was pushing and shoving on both sides but for me it wasn't a reason to caution anybody."
Elizondo went on to say that England coach Sven-Goran Eriksson had said he had been right to send Rooney off.
"Sven-Goran Eriksson went into the locker room after the match and congratulated me for an excellent performance and said that I was right to send Rooney off because it was rough play."
England lost the match on penalties.
Rooney was quoted by British media on Monday as saying he was 'gobsmacked' to have been sent off.
"I want to say absolutely categorically that I did not intentionally put my foot down on Carvalho," the 20-year-old said.
"When the referee produced the red card I was amazed -- gobsmacked.
"I bear no ill feeling to Cristiano but am disappointed he chose to get involved," Rooney added.
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