The People report that McAllister will watch the duo in a special behind-closed-door game tomorrow.
Hull want to sell players after a busy summer in the transfer market, and Leeds need some experience to boost their League One promotion push.
Windass, 39, scorer of the play-off winner at Wembley, has only figured in one Premier League game and may fancy a final challenge. His former club Bradford are also said to be keen.
Centre-half Brown, 31, is settled in the area, so a move west along the M62 may suit him.