The reasoning behind Kay's decision, Flanagan believes, was a lack of first-team opportunities and, when picked, not being able to take a central role.
"On Saturday, at Barwell, I played Matty on the left-hand side of midfield and then I left him out when we played Blyth Spartans on Monday. He came to me afterwards and said he'd had a think and decided he needed a move, a fresh start," said Flanagan.
"I told him it was no problem and would help him as much as I could. I'm happy to waive the seven days' notice providing the approach doesn't come from one of the clubs we face this weekend - Trafford or Witton.
"In many ways it's a great pity because Matty's had a very difficult couple of years. At the start of last season he was looking really fit and scored a lot of goals in the friendlies. Then a taxi ran over his foot in Manchester and he suffered a terrible amount of soft-tissue damage.
"I did my best to be loyal to Matty and I think he understood that and showed me loyalty in return."
Clubs believed to be interested in signing Kay include New Mills and two of his former clubs, Mossley and Ashton United.