Greguš with Copenhagen in 2018
|Full name||Ján Greguš|
|Date of birth||29 January 1991|
|Place of birth||Nitra, Czechoslovakia|
|Height||1.90 m (6 ft 3 in)|
|2013–2014||→ Bolton Wanderers (loan)||0||(0)|
* Senior club appearances and goals counted for the domestic league only and correct as of 4 June 2019|
‡ National team caps and goals correct as of 7 June 2019
In January 2013 Greguš joined English Championship club Bolton Wanderers on loan with Wanderers manager Dougie Freedman stating he would initially be part of the club's development squad. He scored on his development squad debut against Manchester City in a 3–3 draw. After one year at Bolton Wanderers during which he mostly played for the development squad Greguš returned to Banik Ostrava.
Greguš debuted in Slovakia senior team on 31 March 2015 against Czech Republic. In the 49th minute of the game he assisted Ondrej Duda for the winning goal of the match. By the end of the year, he was also fielded for matches against Spain, Switzerland and Iceland.
Two years later, in his 12th cap for the national team, Greguš scored his first goal in the senior squad. This was in the 42nd minute of a qualifying match for a 2018 FIFA World Cup against Malta in Ta'Qali, when Greguš's right-foot shot slipped under Andrew Hogg. At that time, the score was tied 1–1, after an early goal by Vladimír Weiss (2nd minute), followed by 14th-minute equalizer by Jean Paul Farrugia. Slovakia went on to win the game 3–1 and moved to the second position of the Group F table, after 5 of the 10 matches played. After the match, Greguš said that this goal was "so far, the most important" goal in his career.
In 2018, he was fielded for the 90 minutes of the final match of the 2018 King's Cup against Thailand (3–2 victory), winning his first trophy with Slovakia, after being benched in the semi-finals against UAE. Later in the year, he scored his second international goal in a friendly fixture against Morocco, as a part of their preparation for 2018 FIFA World Cup. He scored with a right-foot shot from the outside of the penalty box, after calling the ball ahead Albert Rusnák, who got the assist. Greguš only played the second half of the game, replacing the captain Marek Hamšík. Slovakia lost the game 1–2.
- Scores and results list Slovakia's goal tally first.
|1.||26 March 2017||Ta' Qali National Stadium, Mdina, Malta||Malta||2–1||3–1||2018 FIFA World Cup qualification|
|2.||4 June 2018||Stade de Genève, Geneva, Switzerland||Morocco||1–0||1–2||Friendly|
|3.||7 June 2019||Anton Malatinský Stadium, Trnava, Slovakia||Jordan||1–1||5–1|
- "Ján Greguš". FK Jablonec. Retrieved 17 August 2018.
- "Under-21s: Man City 3-3 Wanderers". Bolton Wanderers FC. 1 February 2013. Retrieved 18 August 2016.
- "Slovakia midfielder Jan Gregus moves to Copenhagen". USA Today. 19 June 2016. Retrieved 18 August 2016.
- "Minnesota United adds FC Copenhagen's Jan Gregus as third designated player". Minnesota Star Tribune. 20 December 2018. Retrieved 20 December 2018.
- "Greguš, Ján". National Football Teams. Retrieved 30 March 2017.