Cristiano Ronaldo's former teammate Paulo Ferreira feels the ace Portuguese forward can continue playing until he is 40.

Ronaldo, 35, equalled Serie A's record for scoring in 11 consecutive appearances for Juventus earlier this month. Ferreira has played in four major international competitions with Ronaldo between 2004 and 2010. "I've known Cristiano for a long time," the former right-back told Goal at the London Football Awards.