2016–2020: Turning Pro, ATP debut Andreev made his debut at ATP level at the age of 15, when he received a wildcard for the qualifications of the
2016 Moselle Open, where he lost to
Michael Berrer. Andreev played as a wildcard at the
2017 Sofia Open in his homeland for the first time, losing in two sets to
Maximilian Marterer in the qualifications. The following year, Andreev received another wildcard, this time for the main draw of the
2018 Sofia Open event, but lost to
Denis Istomin. The 17-year old Bulgarian became the first player born in 2001 to play in the main draw of the ATP World Tour. In the
2019 Sofia Open, Andreev was granted another wildcard for the main draw. The Bulgarian pushed world No. 45
Matthew Ebden to three sets, but ultimately lost in the third set tie-break. A year later Andreev received another wildcard for the main draw at the
2020 Sofia Open, but could not go past world No. 38 and sixth seed
John Millman.
2021: First ATP win, top 350 debut At the beginning of the season, Andreev qualified for the main draw of the
Antalya Open and managed to record his first ATP win defeating
Marsel İlhan in straight sets before he lost to the eventual champion
Alex de Minaur in the second round. Andreev recorded his first Top 100 win at the
Singapore Open, where he defeated world No. 82
Lloyd Harris before losing out to the eventual champion
Alexei Popyrin in the second round. As a result, Andreev climbed to a high-career No. 382 in the ATP rankings. At the
2021 Sofia Open Andreev lost to world No. 62
Miomir Kecmanović after receiving a fourth consecutive year wildcard into the main draw.
2022: Three Challenger semifinals, Top 200, Bulgarian No. 2 In January, Andreev reached his first Challenger semifinal as a qualifier at the
2022 Città di Forlì II where he lost to third seed
Jay Clarke. In April, he also reached the quarterfinals at the
2022 Sarasota Open but retired against fifth seed and eventual champion
Daniel Elahi Galán. In the following months he also reached the round of 16 in four Challengers in
Coquimbo, Colombia in May, and as a qualifier in
Orlando, Florida in June, in
Amersfoot, Netherlands in July and in
Meerbusch, Germany in August where he lost to third seed
Andrea Collarini, third seed
Christopher Eubanks, second seed & eventual runner-up world No. 81
Roberto Carballés Baena and
Damir Džumhur respectively. In August, Andreev reached his first Challenger final in doubles at the
IBG Prague Open, playing alongside
Murkel Dellien, but the Bulgarian-Bolivian duo lost in the title match to
Victor Vlad Cornea and
Andrew Paulson. The Bulgarian's third Challenger quarterfinal showing came at the
Open de Rennes tournament in September, where in the round of 16 Andreev scored his second Top 100 win, overcoming the world No. 95 and third seed
Hugo Grenier after a third set tiebreak. In the quarterfinals, he faced the
2020 US Open champion and former world No. 3
Dominic Thiem, but failed to score another upset, losing out in three sets to the Austrian. Ranked No. 309 at the
AON Open Challenger in Genoa, he entered the main draw as an alternate and started his campaign with a win over former top-100 player
Salvatore Caruso. In the second round, Andreev scored a big upset over world No. 64 and third seed
Corentin Moutet, saving three match points for his third Top 100 win of his career to reach his fourth quarterfinal of the season. With his next straight sets win over
Raúl Brancaccio, he reached his second Challenger semifinal and the top 250, climbing more than 60 positions in the rankings. There he lost to second seed and eventual champion
Thiago Monteiro. Thanks to his successful run in Genoa, he rose to a new career-high of No. 247 on 26 September 2022. He received a special exemption for his next Challenger, the
2022 Open d'Orléans, where he reached again the quarterfinals, for the fifth time in the season, defeating
Ramkumar Ramanathan and again Corentin Moutet, who this time was the top seed, in three tight sets in a three hours match. Next he defeated world No. 98 and sixth seed
Norbert Gombos, his fourth top-100 win in a month, to reach his third Challenger semifinal. He lost to fourth seed
Quentin Halys. As a result, Andreev climbed close to 40 positions in the rankings to world No. 211 on 3 October 2022. The following week at the
2022 Saint-Tropez Open he entered as a lucky loser but lost in the first round to
Stefano Travaglia. At the
2022 HPP Open in Helsinki, he reached the quarterfinals as an alternate defeating Jay Clarke and
Mattia Bellucci. As a result, he moved 13 positions up to a new year-end career-high of No. 207 on 21 November 2022. The next day he further reached the top 200 with a round of 16 showing at the Challenger
2022 Copa Faulcombridge in Valencia with a win over sixth seed
Timofey Skatov. The day after he was confirmed as a participant at the
2023 United Cup as part of the Bulgarian team. He reached another quarterfinal defeating
Ivan Gakhov. He lost to Serbian
Nikola Milojevic in a close three set match despite winning the first set with a bagel at 6–0. He reached a new career-high singles ranking of No. 197 moving 10 positions up on 28 November 2022 making him the Bulgarian male player No. 2 in the rankings ahead of
Dimitar Kuzmanov. He reached another quarterfinal at the
2022 Maspalomas Challenger but he withdrew from the match due to injury against another Serbian
Dušan Lajović. He moved to No. 193 in the singles rankings ending his season on 2 December 2022.
2023: United Cup debut, First Grand Slam qualifications He made his
2023 United Cup debut in the mixed doubles match alongside
Gergana Topalova where they lost to the top seeded team of
Maria Sakkari and
Stefanos Tsitsipas. At the
2023 Australian Open qualifications, he defeated
Francesco Maestrelli, and 15th seed
Jurij Rodionov but fell to 20th seed
Zizou Bergs in the final round. He regained the Bulgarian No. 2 ranking on 20 February 2023. He reached also the third round of qualifying at the
2023 French Open but lost to Major debutant
Genaro Alberto Olivieri. He lost in the first round and second rounds of qualifying at
Wimbledon and at the
US Open falling to
Michael Mmoh and
Borna Gojo respectively.
2024–2025: Maiden ATP Challenger title, hiatus, out of top 500 At the
2024 Zadar Open, Andreev reached his maiden
Challenger final defeating
Manuel Guinard, wildcard
Matej Dodig,
Enrico Dalla Valle and
Timofey Skatov. He lost to
Jozef Kovalík in the final. As a result he returned to the top 230 in the rankings on 8 April 2024. In August 2024, Andreev won his maiden title at the
CT Porto Challenger, defeating fourth seed
Carlos Taberner in the final. He became the fifth Bulgarian to win a challenger title. As a result, he returned to the top 205 in the rankings on 9 September 2024. ==Grand Slam performance timeline==