Veteran Uruguayan striker Diego Forlan shared his thoughts through his column in The National about longtime Real Madrid goalkeeper Iker Casillas leaving the club to join Porto.

Forlan started his column with his conversation with Barcelona striker Luis Suarez who asked when he knew it was time to retire from international competition.

After that the 36-year-old footballer wrote, "It sounds confusing, but there's no clear-cut way of ending your career, or leaving to go to a smaller club, no definite date when you leave and everyone agrees it's the right time."

"I thought about it this week when I saw Iker Casillas announce he was leaving Real Madrid, a great club. I have huge respect for Porto, another great club who consistently challenge for titles. They identify players, develop them and then sell them on for a profit, but let's not pretend they're Real Madrid, one of the biggest clubs in the world. It's a step down for Casillas, just as Robin van Persie leaving Manchester United for Fenerbahce is also a step down," Forlan discussed in his column.

Casillas still had two years left in his contract with Real Madrid but decided to leave after struggling for the past three seasons and has constantly been linked to trade moves, ESPN reported.

Forlan also compared Xavi's departure from Barcelona and Casillas leaving Real Madrid.

He stressed that Xavi left after Barcelona won the treble but never departed the club when they were unable to win trophies.

Forlan added, "But what would have been the reaction for Xavi had he left the previous year when Barca won nothing? It wouldn't have been the happy exit it was this time. Casillas could have left Madrid a year ago, and walked out as a European champion."

He also wrote in his column that Real Madrid should have treated Casillas better by protecting him from the media and the fans' criticisms, but they did not and let him defend himself which seemed like the club's way of letting him go.