[5] He made his debut for Ludogorets Razgrad II in B Group on 4 April 2016 in match against Neftochimic Burgas.

[6] After the injury of Vladislav Stoyanov in March 2017, Numov became the second-choice goalkeeper and on 18 April 2017 he made his debut for the first team in the Bulgarian Cup match against Litex Lovech, keeping a clean sheet in a 4–0 win.

[11] Naumov ended the campaign with only five appearances due to a shoulder injury and noted that he hoped to become the first-choice goalkeeper in Ludogorets in the following season.

[17] Naumov made his debut for Bulgaria U21 on 27 March 2018 in a European Under-21 qualification match against Slovenia U21, keeping a clean sheet in a 3–0 win.

[19] He made his debut on 31 March 2021, keeping a clean sheet for the draw against Northern Ireland for the 2022 FIFA World Cup qualification.