Pirola joined the youth academy of Inter Milan in 2015.[3] Pirola made his senior debut with Inter in a 4–0 Serie A win over SPAL on 16 July 2020.[4]
Loan to Monza
On 5 October 2020, Pirola moved to newly promoted Serie B side Monza on a one-year loan.[5] He made his debut on 27 October 2020, in a Coppa Italia third round match against Pordenone;[2] Monza won on penalties, with Pirola playing the whole 120 minutes.[6] Pirola played his first Serie B match on 22 December,[2] in a 2–0 win over Ascoli at home.[7]
On 14 July 2021, Pirola re-joined Monza on another one-year loan, with an option to buy for Monza and a counter-option for Inter.[8]
Salernitana
Pirola joined Salernitana in the Serie A on a one-year loan, with an option to buy and counter option in favour of Inter.[9] At the end of the season Salernitana triggered the option to buy, making the transfer permanent.[10]
Olympiakos
Pirola joined Olympiakos in the Greek Super League on a three-year contract for a €3 million fee.[11]