On 1 September 2018, Dybala made his 100th Serie A appearance for Juventus, coming on as a late second-half substitute in a 2–1 away win over Parma. On 2 October, Dybala scored a hat-trick in a 3–0 home win over Young Boys in the Champions League. In Juventus's following Champions League group match on 23 October, Dybala scored the only goal of the game in a 1–0 away win over Manchester United. With the arrival of Cristiano Ronaldo, Dybala was often deployed out of position in a deeper role by manager Allegri during the 2018–19 season; as a result of this positional switch, as well as struggles with injuries, and difficulties with his manager, Dybala suffered a loss of form, and his goalscoring output decreased significantly, as he managed to score only five goals in 30 league matches, and 10 goals across 42 appearances in all competitions. However, Juventus managed to retain the Serie A title.
In May 2018, Dybala was named in Argentina's preliminary 35-man squad for the 2018 FIFA World Cup in Russia; later that month, he was included in Jorge Sampaoli's final 23-man squad for the tournament. He made his World Cup debut in Argentina's second group match on 21 June, coming on as a second-half substitute for Enzo Pérez in the 68th minute of an eventual 3–0 defeat to Croatia. This was his only appearance in the tournament, as Argentina were eliminated in the round of 16 on 30 June, following a 4–3 defeat to France.
A versatile forward, he is capable of playing in any offensive position: he started out playing as a left winger for Instituto in Argentina towards the beginning of his career, but since moving to Italy he has been deployed in a variety of attacking roles, including as a main striker, as a centre-forward, as a supporting forward, as an attacking midfielder, in a free role as a wide playmaker, as a right-sided inside forward, as a false attacking midfielder, as a false-9, or even as an inverted winger on the right flank, where he is able to cut into the centre and curl shots on goal with his stronger left foot. He has also been used in a free attacking role on occasion, in which he is given licence to roam about the final third of the pitch, and either drop into the middle, or switch between the flanks, due to his ability to create from the left or cut inside and score from the right. Because of his work-rate and involvement in the build-up of his team's attacking plays, in addition to his goalscoring ability, former Juventus manager Massimiliano Allegri even deployed Dybala as an offensive-minded central midfielder on occasion (known as a "mezz'ala", in Italian), and described him as a "box-to-box player" ("tuttocampista", in Italian) in 2018. He has also operated in a deeper playmaking role on occasion. Dybala is also accurate from both free kicks and penalties. His playing style has drawn comparisons with compatriots Sergio Agüero, Javier Pastore, Carlos Tevez, Omar Sívori, Diego Maradona, and Lionel Messi, as well as former Italian forwards Vincenzo Montella, Alessandro Del Piero, and Roberto Baggio; the latter described Dybala as the number 10 of the future in 2017. Widely considered to be a highly talented prospect in world football, in 2014, Don Balón named him one of the 100 most promising young players in the world born after 1993. Despite his talent, however, his mentality, consistency, and leadership qualities have come into question at times in the media.