Aron Gunnarsson says he is surprised to see former club Coventry struggling at the foot of the Championship table, but has warned Cardiff against complacency.
Fourth-placed Bluebirds visit the Ricoh Arena on Tuesday in search of a fourth successive league victory.
Coventry have not won in six and have lost three in a row, with only goal difference keeping them off the bottom.
But Gunnarsson said: "I know how good they are and I know what they are capable of."
The 22-year-old midfielder joined Cardiff in July having made 133 appearances in three seasons at Coventry.
And he added: "It's going to be a hard game for us even though they are struggling at the moment and are second bottom in the league.
"They are a good footballing side - they play some nice stuff. But if we turn up and play like we did against Reading and work hard for each other then we'll get a good result there."
Saturday's 2-1 victory at Reading extended Cardiff's unbeaten run to five games and avoiding defeat at Coventry would lift them above Middlesbrough into third place.
Gunnarsson is one of 11 new players recruited by Malky Mackay since taking over as Cardiff manager in June.
The Iceland international has established himself in the Bluebirds team, starting 13 of their 17 Championship games, and he believes the new recruits have done well to gel together so quickly.
"We're blending in quite well at the moment and hopefully we'll keep that going," he said.
"We're working for each other and that the most important thing.
"I haven't really noticed anyone speaking about us [as promotion contenders] but it's a good thing.
"We just have to keep our run going and see where it takes us."