Town have played every midweek since Jewell replaced Roy Keane in January - with one international fixture as well - but were not in action this week to prepare thoroughly for the trip to Cardiff.
Former Cardiff man Kennedy said: "When you are playing Saturday, Tuesday, Saturday, Tuesday you are either basically playing, resting or travelling with the odd training day in-between.
"So the new management team deserve a great deal of credit for what they have already achieved.
"They have not had the opportunity they would have wanted to have fully got their thoughts and tactics across.
"With the time they have had they have left no stone unturned and the training has been intense. This week is certainly not a holiday period as the Championship does not work like that."
Source: PA
Source: PA