In July 2009, Popa signed a contract with Universitatea Cluj. Although he showed impressive skills and helped the team get promoted to the first division, he left the club after one year.
Concordia Chiajna
In 2010, Popa joined Concordia Chiajna. He contributed to the club's promotion to the first division and was kept for the following season.
He played over 200 games during his spell with the capital-based club.
Reading
On 27 January 2017, it was announced that Popa agreed to transfer to English team Reading after reaching the final six months of his contract with FCSB.[4] The transfer was made official three days later, with Popa signing with Reading until the summer of 2020.[5]