2011–12

In January 2012, Ognyanov joined Botev Plovdiv and helped the team to get a promotion to A Grupa.^[9] He quickly established himself as a key player and took part in 10 games.^[10]

2012–13

Although Botev Plovdiv signed with a lot of new players Ognyanov remained a key player during season 2012–13. He participated in 28 matches in A Grupa and scored 6 goals. Botev Plovdiv finished the season on the 4th place.

2013–14

Botev Plovdiv was allowed to participate in the UEFA Europa League despite finishing on 4th place of A Grupa during the previous season because of the financial troubles at CSKA Sofia.^[11][12] Marian participated in all six games of the team in the tournament and demonstrated an excellent partnership on the field with Todor Nedelev. During the European campaign Ognyanov scored two goals in the home wins against FC Astana and HŠK Zrinjski Mostar.^[13][14]

On 5 December 2013, Ognyanov came on as a substitute and scored the winning goal for the 2–1 victory over CSKA Sofia.^[15]

Botev Plovdiv finished again on the 4th place of A Grupa and lost the final for the Bulgarian Cup. Despite the loss Botev Plovdiv qualified for UEFA Europa League. Ognyanov played in 5 games for the Bulgarian Cup and 27 games in A Grupa, primary as a defensive midfielder.^[16] He scored one goal in each home victories over Pirin Gotse Delchev and CSKA Sofia.^[17][18]

2014–15

Despite the financial crisis Ognyanov was among the few first team players who did not leave the club in the summer of 2014. He accepted a reduction of his salary and remained for season 2014–15.^[19]

Ognyanov scored twice against A.C. Libertas in the 4–0 home win in the first qualifying round of 2014–15 UEFA Europa League.^[20] He participated again in all four games of Botev Plovdiv in the UEFA Europa League and made three assists. With four goals Marian shares the third place in the list of top goalscorers for Botev Plovdiv in the European football tournaments.^[21]

On 23 September, Marian Ognyanov scored the second goal for the 0–4 away win against Lokomotiv Mezdra in the first round of the Bulgarian Cup tournament.^[22] In the next round of the Bulgarian Cup Marian assisted for the late equalizer of Aleksandar Kolev against Lokomotiv Plovdiv.^[23]

Marian Ognyanov scored his first goal of the season in A Grupa from a free kick on 2 November. Unfortunately his goal was not enough and the team of Botev Plovdiv was defeated with 2–1.

As of 26 November 2014, Mariyan Ognyanov was the player with most assists during the season so far in Bulgaria. He assisted for 6 goals in A Grupa as well as for 4 goals in other official tournaments.^[24]

Ognyanov started 2015 with a fabulous goal and an assist for the 3–0 home win over PFC Marek Dupnitsa.^[25] On 10 March Mariyan was again among the best players on the pitch in the next round of A Grupa. Ognyanov prove his creativity and passing abilities and was involved in both goals for the 0–2 away win in the derby match against the local rivals Lokomotiv Plovdiv.^[26] Ognyanov missed the game with CSKA Sofia due to a ban, and on 22 March he was again in the starting lineup for 0–0 draw with Ludogorets Razgrad.^[27] On 18 April, Ognyanov scored a goal for the 1–1 draw with Beroe Stara Zagora.^[28]

The contract of Mariyan Ognyanov with Botev Plovdiv expired at the end of the season and he left the team.^[29] In an interview Ognyanov stated that he is grateful for everything and he hopes one day to play again for Botev Plovdiv.^[30] On 17 June, Mariyan joined the Romanian professional football club Târgu Mureș on a free transfer, but he left a week later due to personal reasons and returned to Botev Plovdiv.^[31]

2015–16

Ognyanov started his 5th season at Botev Plovdiv with a game against his ex-team Levski Sofia in the first round of A Grupa. He missed a penalty and the game ended in a 1–1 tie.^[32] After the game Mariyan Ognyanov apologized to Botev Plovdiv supporters.^[33]

Ognyanov missed the second round in A Grupa and returned in the starting lineup for the 1–1 draw against the local rivals Lokomotiv Plovdiv. He was the captain of the team due to the absence of Yordan Hristov who received a red card in the previous match. Ognyanov made a brilliant assist for the goal scored by Aleksandar Kolev.^[34]

On 22 November, Ognyanov made the assist for the winning goal scored by Nico Varela during the away game against Cherno More Varna.^[35] A week later, on 29 November, Ognyanov provided the assist for the second goal of Gregory Nelson during the 4–2 away defeat from Litex Lovech.^[36]

On 7 April 2016, Botev Plovdiv announced that the expiring contracts of Ognyanov and the goalkeeper Valentin Galev will not be renewed for the next season.^[37] A week later Nikolay Kostov, the head coach and manager of Botev Plovdiv at that time, explained that he expected better performance and more engagement to the development of the younger players from Mariyan.^[38] On 18 April, the contacts of Ognyanov and Galev were terminated on mutual agreements.^[39] On 19 April Ognyanov received a medal of honor and special t-shirt to celebrate his 133 appearances in official games for Botev Plovdiv.^[40]

Mariyan Ognyanov spent almost 5 seasons in Botev Plovdiv. He played in 100 games in A Grupa, 10 in B Grupa, 12 for the Bulgarian Cup, 1 for the Bulgarian Supercup and 10 games in UEFA Europa League.^[41]