With Ninjas in Pyjamas, Kněžínek began his LCS career during the summer split of season 3. By the end of the split, the team finished the regular season in 5th place, making it to the playoffs, where they finished 6th overall. This, unfortunately, lead Ninjas in Pyjamas to be relegated to the challenger series, where Kněžínek would stay for the whole duration of season 4, before later leaving the disbanding NiP. Kněžížek was then picked up by the Copenhagen Wolves before the start of season 5 spring split, where he and the team finished 6th. In the summer split of season 5, the Copenhagen Wolves were much less successful, finishing in last place, forcing them to be auto-relegated.[2] Meaning Kněžínek's contract expired and he announced his free agency on November 1, 2015.[3] He was picked up by North American team Renegades on January 6,[4][5] where he is currently playing the season 6 spring split.[6] Renagades finished 8th in the LCS, and Kněžínek left the team after the disappointing finish.
He joined H2k on May 8, 2016, ahead of the EU LCS Summer 2016 split, replacing FORG1VEN at AD Carry as the latter was conscripted into the Greek Army.[7][8][9][10] However, FORG1VEN later had his military service commuted, and transferred to Origen.
On July 27, 2016, H2k announced that Kněžínek would step away from the roster due to persistent tendonitis.[11] The team stated that FORG1VEN would take his place on the starting roster.[12] Signed by Tempo Storm in December 2016.[13][14]
In 2020, Kněžínek stepped away from competitive play and signed with 100 Thieves as an assistant coach.[15]
With the help of Kněžínek's coaching abilities, 100 Thieves became a title contender, which they've successfully accomplished during the 2021 LCS Summer split. 100 Thieves didn't change the roster even after struggling during the 2021 Worlds championship, finishing 3-3 in group stage.
Kněžínek became the head coach of the 2022 100 Thieves roster and despite tough losses in finals of both spring and summer split, the team had consistent results and great performances.
After another disappointing Worlds championship performance, Kněžínek signed a contract with Evil geniuses.
After struggling through the spring split of LCS's 2023 season, Evil geniuses managed to reach semifinals in the playoffs. But losing 0-3 to Golden Guardians destroyed any hopes of playing MSI 2023. Aleš Kněžínek left the team soon after spring season ended.
