Keane's fellow panelist Ian Wright also backed Ronaldo in his long-running battle with Messi, as he took his goal tally at Russian Federation 2018 to four after his victor against Morocco on Wednesday.
The victory against Morocco put Portugal on four points in Group B and in control of their own fate heading into the group-stage finale against Iran on June 25.
Ronaldo netted a hat-trick in Portugal's opening match with Spain, before going on to score the only goal of their 1-0 win over Morocco.
There's an old joke that Portugal (and Greece) can't play great soccer because every time they get a corner, they open a cafe.
"Cristiano Ronaldo is like a port wine, he changes as he ages", Santos said.
"We gave it everything, but you saw [the ball] just didn't want to go in", he added.
Uruguay and Russian Federation have both clinched a spot in the round of 16 of the FIFA World Cup in Russian Federation on Wednesday thanks to the 1-0 win over Saudi Arabia by La Celeste in their second group stage match.
O's boss Edinburgh believes if Messi can help his country win this year's World Cup it would ensure he will forever be remember as a great on the worldwide stage.
Get the latest World Cup news updates. "I hope you will tell Messi to play a better match against Nigeria", another person commented, referring to the upcoming third and final Group D game in St. Petersburg.
We are a week into the 2018 FIFA World Cup and there has only been one man who has been making the headlines all over the media.
Morocco defender Mehdi Benatia claimed his side proved they belong at the World Cup after a 20-year absence, but the Juventus centre-back conceded there was simply no answer to Ronaldo.
Having been thumped 5-zip against Russian Federation in their opening Group A fixture, Saudi Arabia had nothing to lose by making wholesale changes for their do-or-die encounter with Uruguay on Wednesday afternoon. "I´m very happy with the performance".