Hudson received his 10th yellow card of the season in last weekend's defeat at Brighton and fellow defender Smith was sent off for two bookable offences in the same match.
Midfielder Jonathan Hogg returns to contention after serving a one-game ban, but winger Sean Scannell is expected to miss out again due to a knee injury.
Striker Ishmael Miller (hamstring) remains doubtful, but defender Kyle Dempsey (knee) could return to contention.
Cardiff defender Lee Peltier misses out against his former club through suspension.
Peltier was sent off in last weekend's 2-2 home draw with Rotherham after picking up two yellow cards and Fabio Da Silva is set to deputise at right-back.
Bluebirds boss Russell Slade is also likely to be forced into a change in attack after Joe Mason joined Wolves for an undisclosed fee.
Lex Immers could make his first start since joining on loan from Feyenoord and Idriss Saadi is in contention to rejoin the squad for the first time since suffering a serious hamstring injury in November.
Match officials:
Referee: Mr David Webb (County Durham)
Assistant: Mr Nicolas Hopton (Derbyshire)
Assistant: Mr Declan Ford (Lincolnshire)
Fourth Official: Mr Mark Heywood (Cheshire)
Match stats:
- Huddersfield are winless in five league games against Cardiff (D2 L3) stretching back to August 2012.
- The Bluebirds have kept clean sheets in five of their last seven league meetings with Town (W4 D2 L1), including the last two at the John Smith's Stadium.
- The Terriers have scored only two goals in their last seven league games against Cardiff, with those goals coming 11 years apart - Murray Wallace in August 2014 and Andy Booth in January 2003.
- No Cardiff player has scored on their previous three visits to Huddersfield - the last one to score there was Peter Thorne who scored a brace in April 2002.
- Huddersfield and Cardiff met in the League Cup in August 2011, a 5-3 win for the Bluebirds. There were more goals in that game (8) as there have been in the previous five league encounters (7).
- Cardiff defeated Town earlier in the season, a 2-0 win in September courtesy of goals from former Terriers winger Anthony Pilkington and Joe Mason.
Huddersfield v Cardiff City.
Saturday 3:00pm.