Tariq Sims' career with the Cowboys is over after he accepted a five game ban for his shoulder charge on Justin Hodges, while Manly will also be without key forward Anthony Watmough for their semi-final against the Bulldogs.
The Cowboys declined to fight the Grade 3 charge, with loading from a prior non-similar offences and 18 carry-over points ruling Sims out for his next five games.
Sims is off to Newcastle next season, so the early guilty plea means he has played his last game in Cowboys colours. Depending on how far North Queensland progress in this year's finals series, Sims could sit out up to the first month of 2015 for the Knights.
An injury-hit Manly side took another blow with Watmough's one-match ban for a Grade 1 dangerous throw charge on Rabbitohs fullback Greg Inglis ruling him out of this weekend's game.
Watmough's previous indiscretions - he missed four matches earlier in the year for a similar tackle on Nate Myles in Origin II - meant the Sea Eagles were reluctant to challenge the charge.
Skipper Jamie Lyon, who was also involved in the tackle on Inglis, will be free to play after taking the early guilty plea due to his clean record.
Brisbane's Ben Barba also escaped a ban by taking the early guilty plea for a Grade 1 Dangerous Contact charge for applying unnecessary leg pressure to Kyle Feldt.
Wests Tigers Holden Cup player Tyler Cassel has also accepted a four-week suspension for his Grade 4 Dangerous Contact - Contact with the Kicker charge, and will miss the rest of the finals series.