Updated

Nyon, Switzerland (SportsNetwork.com) - Celtic has been reinstated to the Champions League after Legia Warsaw had its third qualifying round second-leg win over the Scottish side overturned because the team fielded an ineligible player.

UEFA handed down the ruling on Friday after Legia's Bartosz Bereszynski was an 86th-minute substitute in his team's 2-0 second-leg win on Wednesday, handing the Polish side a 6-1 aggregate victory.

Bereszynski was sent off in Legia's final Europa League match last season, earning him a three-game ban which he thought he had served after sitting out both legs of his team's second qualifying round win over St Patrick's and the first leg against Celtic.

However, UEFA's investigation focused on whether or not Bereszynski was registered in Legia's team against St Patrick's in order for the suspension to be served.

Under UEFA guidelines, "only eligible players can serve pending suspensions," and with Bereszynski having not been registered against St Patrick's, he technically still needs to serve a further two-game suspension.

With Bereszynski being declared ineligible, Celtic was awarded a 3-0 win in the second leg through forfeit, leaving the aggregate total at 4-4 between the two teams, with Celtic advancing on away goals.

A statement from UEFA read: "Legia have been sanctioned for fielding an ineligible player [article 18 of the UEFA Champions League regulations and article 21 of the Disciplinary Regulations]. The match has been declared as forfeit meaning Legia Warsaw have lost the match 3-0.

"As a consequence, Celtic have qualified for the UEFA Champions League playoffs on away goals [agg: 4-4] and Legia will compete in the UEFA Europa League playoffs."

Legia now has five days to appeal the ruling.