Skalák started his professional career at AC Sparta Prague, spending time on loan at MFK Ružomberok, 1.
[2] Skalák joined Football League Championship side Brighton & Hove Albion on 1 February 2016 for an undisclosed fee, believed to be £1.2 million.
[7] He eventually scored his first league goal for Millwall on 22 July 2020, the final day of the extended 2019–20 season in a 4–1 win against Huddersfield.
[8] On 8 February 2021, Skalák joined Czech First League side FK Mladá Boleslav for an undisclosed fee.
He was called up for the senior national team for the first time on 25 August 2015 to face Latvia and Kazakhstan in the UEFA Euro 2016 qualifying round but did not play in those matches.