The club was still in talks with Castleford Tigers yesterday in an attempt to complete the paperwork on a short-team loan deal for the 22-year-old half-back.
Coach Jon Sharp believes Thackeray, who has made ten Super League appearances for Cas this year, will be a big hit in NL1: "He's a natural ball-player, difficult to defend against and difficult to read.


"His athleticism, speed and eye for a gap will cause teams in this division problems. There are little things he can improve and that's his challenge while he's here but he's full of enthusiasm and playing first-grade rugby will help him."
Ex-Hull FC utility Thackeray will become the second Cas player in seven days to make the switch to Post Office Road - Academy captain Jack Lee made the move last week.


He is not expected to be the only player with Super League experience on debut against the Reds. Featherstone are close to finalising a deal to bring a hard-running Hull-based prop to the Chris Moyles Stadium before tomorrow's signings deadline.
Paul Handforth, who was suspended for the Celtic game, misses Sunday's game - he is on holiday - and Sharp has the option of starting with Thackeray or sticking with stand-in stand-off Tommy Haughey, who filled in handsomely to score a hat-trick at the weekend.


But with no injuries to report and two new bodies expected to be on board, Sharp is almost certain to make changes to his 17.
Meanwhile, reports last week that Warrington hooker Mark Gleeson had signed for the club were off the mark, according to club officials.


"Reports in the media, from other sources, that he had signed for Featherstone were premature. Those reports did not come from Featherstone Rovers," a statement said.
The following day Gleeson joined Featherstone's NL1 rivals Halifax FC.