Chelsea were unable to sign players during the summer transfer window and the ban was due to end in February.
Even though Chelsea are now cleared to spend £150million in the January transfer window, the club has released a statement slamming the "deeply unsatisfactory" approach to their case.
Farewell to the best transfer ban in memory.
The club, now fourth in the Premier League, had filed an appeal with CAS in June.
Chelsea closed out the statement by saying that although the protection of minors is important, 'if Federation Internationale de Football Association continues to impose inconsistent and unequal sanctions on clubs then it will not only undermine the very goal of the regulations, but it will also bring into doubt the game's confidence in Federation Internationale de Football Association being able to appropriately regulate this important area'.
"Furthermore, Chelsea sought clarification from the Premier League in 2009 about whether it needed to apply for permission to register players in this category. We are grateful that this appears to have been corrected by the CAS".
Emery was sacked to save Arsenal's season
Vieira was interviewed by Arsenal as a potential replacement for Arsene Wenger previous year before Emery was appointed. Arsenal failed to win a game in their last seven games, with a number of points dropped at home in winnable games.
World football's governing body since delved deeper into Chelsea's dealings on the transfer market over recent years, with phase two of their inquiry having taken a close look at how the Blues have registered players in their academy system of late.
Chelsea will now be able to sign new recruits in January, with a left-back a priority for manager Lampard. "Now we know. It's a positive outcome for us", Lampard told his pre-match press conference.
Chelsea have some exciting young targets listed as potential targets, who look like they could add extra quality to Lampard's young vibrant side and the future looks exciting for supporters.
A general view of Chelsea's Stamford Bridge stadium.