Aston Villa striker Darren Bent is set to make a loan move to Brighton in the next 48 hours, according to Sky sources.
Juan Cala wants to find 'another club ASAP' and believes Cardiff have acted without respect towards him.
Kiernan had a temporary spell at Griffin Park in November, making seven appearances for Uwe Rosler's side before returning to the Latics.
The Republic of Ireland Under-21 international featured in both central defence and midfield and played a key role in Brentford's win over Sheffield United in late November, helping to set up the first goal.
He is available for selection for the Bees' League One game at Oldham on Saturday.