On 10 December 2010, it was reported that Casas' former youth clubLibertad would sue Panathinaikos for breach of trust. Casas had travelled to Greece in 2009 to trial with Panathinaikos after Libertad had received an invitation from Panathinaikos to trial the player for 30 days. According to Libertad, Panathinaikos had asked Libertad for a one-month extension as the player was passing the trials. During that time, Panathinaikos had convinced Casas to continue at Panathinaikos without Libertad's permission and using the invitation as a trick and the player signed for the Greek club when he turned 18 years old. Libertad detailed that the club deserves expenses due to forming the player. "We brought him from the interior, we looked after him, we gave him food, we gave him home health, we formed him for four years to become a Libertad player and he is taken. It is a similar case to Juan Iturbe. The player had signed with the club on a Spanish passport, and was team mates with Greece U21 player Giorgos Machlelis and Australia U20 player Robert Stambolziev.
22 de Septiembre
Casas featured for 22 de Septiembre during the 2015Primera División B Nacional. In October 2015, he featured during the promotion play-offs against Liga Ovetense as the latter eventually gained promotion to the 2016 División Intermedia. Subsequently, 22 de Septiembre were then forced to play a promotion play off against the runner-up of the Primera División B Metropolitana in order to ascend to the 2016 División Intermedia. In November 2015, Casas featured in both fixtures of the play-off against Club Fulgencio Yegros as 22 de Septiembre were defeated 4−2 on penalties after a 2−2 aggregate score.
Casas made his first appearance for the club in Round 1 of the 2016 División Intermedia, playing a full 90 minutes of a 3−2 away victory against Ovetense. He then played a full 90 minutes in a 4−0 thrashing against Sport Colombia the following week. He would not play again until round 7 in a 1−0 away defeat against Sportivo Iteño. On 10 July 2016, he scores for the club in a 1−1 draw vs Ovetense.
22 de Septiembre
Casas rejoined Club 22 de Septiembre in 2017 as they were promoted to the División Intermedia having won a promotion play off, the same promotion play off that the player had played in during 2015.
