Buckle played alongside Hughton at Brentford when the former Republic of Ireland defender was coming towards the end of his career.
"We played together and I followed his career, we have met quite often along the way and kept in contact," Hughton said at a press conference.
"Paul was always very enthusiastic and knowledgeable, so it is no surprise to see his path go into manager, so aside from Saturday of course, I wish him all the best."
Hughton is set to make some changes, as he did for the 3-0 third-round win at Peterborough. However, the Norwich manager will not be taking the Hatters challenge lightly.
"Although Luton are a conference team, they are a big name and a team with a very good history, they still get a very good support and at their level have very good players," he said.
"We are very conscious of what can happen, but it was the same when we played Peterborough in the last round. This is what cup football is all about and we have to be very guarded."
Norwich's win at London Road has been their only success in the last seven, losing five Premier League games in that poor run.
Hughton is seeking a positive response from last weekend's 5-0 mauling at Liverpool, which would set things up nicely for the visit of Tottenham next Wednesday night.
"We have been here before, as most clubs have been at our level, there is only one reaction you want and that is to bounce back from it," said Hughton.