[8] However, he made a successful comeback by playing 15 games in the regular season with four shutouts and a save percentage of 94.58 percent.

During the playoffs, he played as the primary goaltender for 13 games with a save percentage of 93.56 percent,[9] helping his team win bronze medals.

On 21 May 2018, Lankinen signed a two-year, entry-level contract with the Chicago Blackhawks of the National Hockey League (NHL).

[11] In his second season with the Blackhawks' American Hockey League (AHL) affiliate, the Rockford IceHogs, in the 2019–20 season, Lankinen made 21 appearances, earning eight wins and represented the IceHogs as the teams' lone representative at the 2020 AHL All-Star Game.

On 5 March 2020, Lankinen was ruled out for the remainder of the 2019–20 season after undergoing shoulder surgery, with a recovery period of five months.

As a free agent from the Blackhawks, on 14 July 2022, Lankinen was signed to a one-year, $1.5 million contract with the Nashville Predators.

[20] Lankinen likes to read and names Sapiens by Yuval Noah Harari as his favourite book.