[2] Tsonev scored his first goal for Levski on 18 September 2013, in a 4–0 win over Pirin Gotse Delchev in the first round of the Bulgarian Cup.

On 26 October, Tsonev made his first league start in a 1–0 home win over Botev Plovdiv, but was sent-off after 68 minutes.

Despite being simultaneously injured for a prolonged period, they gained somewhat of a cult status among fans due to their loyalty to the club at a time of financial hardship.

After joining Ukrainian club Chornomorets Odesa on a two-and-a-half-year contract in January 2022, he was forced to seek another team following the 2022 Russian invasion of Ukraine.

[7] Tsonev received his first call-up for the senior Bulgarian squad on 29 August 2018 for the UEFA Nations League matches against Slovenia and Norway on 6 and 9 September.