"It happens, it's football. Who's out there risks it. I'm calm, because I know I'm going to be back well in one or two weeks with no problem."
Goal understands Ronaldo began his treatment on Thursday, undergoing physiotherapy for the injury.
However, the full extent to Ronaldo's problem is still not known, leaving his status for Juventus' upcoming matches uncertain as no further tests are planned for Thursday.
The current timeline also has him a doubt for the game against AC Milan on April 6, though the club's greater concern is likely the match following midweek against Ajax in the Champions League quarter-finals.
Those tests will reveal a better timeline on Ronaldo's recovery time, and his odds at getting fit in time for the first leg on April 10 at the Johan Cruyff ArenA.
Even if Ronaldo's personal prediction is accurate, the longer end of his "one or two weeks" timeline would put him in a race against time to be fit for the contest.
Ajax is hoping to repeat against Juventus what they did to Ronaldo's former side Real Madrid, as the Eredivisie club stunned the Liga giants with a 4-1 victory at the Bernabeu.
Trailing 2-0 after the first leg in Spain, Ronaldo scored all three goals in the return fixture, including a spot-kick in the 86th minute which proved the difference for the Serie A champions in the tie.
The star man has four goals and two assists this year in the Champions League, to go along 19 goals and eight assists in Serie A in 2018-19.