The 2010 Magpies premiership star was a surprise inclusion in Collingwood's list of players released for playing duties over the opening weekend of AFL fixtures with just two matches and both outside of Victoria.
Thomas, 25, is on the edge of full recovery from ankle surgery he had late last year, but has already been ruled out of the Pies AFL premiership season opener against North Melbourne on Easter Sunday.
The nippy midfielder could play in a Magpies reserves game and potentially even a VFL Round 1 clash before pressing for a return to the seniors by about Round 3.
Collingwood fronts a grudge match against 2010 premiership coach Mick Malthouse and his new outfit Carlton in AFL Round 2 on Sunday April 7.
Thomas could still be making his way back into match conditioning with a reserves outing the day before against North Ballarat.
The Pies confront another possible epic showdown in Round 3 with star-studded Hawthorn at the MCG on Sunday April 14.
The Pies also gained AFL permission for other premiership defender Nathan Brown and versatile Tyson Goldsack to play, as well as nippy midfield veteran recruit Clinton Young, who is completing an injury-interrupted pre-season after crossing from Hawthorn as a free agent.
Carlton won permission for veteran Heath Scotland to play in the seconds as the Blues reigning fairest-and-best serves a club imposed suspension after he pleaded guilty to an assault charge.
Scotland, 32, has been banned by Blues officials for the opening two AFL games against Richmond and the Pies.
The Western Bulldogs look likely to send star on-baller Shaun Higgins and lead ruckman Will Minson into their reserves for match-conditioning after mixed pre-season programs.
The Bulldogs launch their AFL premiership season against this summer's NAB Cup series winners Brisbane in Melbourne on Easter Saturday.
Richmond have received permission for veteran midfielder Chris Knights to play with their VFL affiliate as he refines match-conditioning after a late start from crossing from Adelaide.
Carlton appear to want big ruckman Robbie Warnock to get more match-conditioning before he wins a senior team starting berth ahead of Shaun Hampson against the Tigers.
It seems unlikely Warnock would play in a reserves engagement at the weekend and recover in time to front-up again on Thursday against the Tigers at the MCG in such a potentially hectic clash.
AFL PERMISSION to PLAY list
Brisbane Lions - nil.
Carlton - Tom Bell, Ed Curnow, Troy Menzel, Heath Scotland, Tom Temay, Robert Warnock.
Collingwood - Nathan Brown, Tyson Goldsack, Ben Kennedy, Jackson Paine, Dale Thomas, Marley Williams, Clinton Young.
Geelong Cats - nil.
Gold Coast Suns - nil.
GWS Giants - nil.
Hawthorn - nil.
Melbourne - Dominic Barry, Sam Blease, Mitch Clark, Mitchell Clisby, Jack Fitzpatrick, Dean Kent, Tom McDonald, Jordie McKenzie, Nathan Stark, James Strauss, Rory Taggert, Jack Trengove, Josh Tynan, Jack Viney.
North Melbourne - nil.
Port Adelaide - Brett Ebert, Domenic Cassisi, Cameron Hitchcock, Tom Logan, Robbie Gray, Ben Newton, Jack Hombsch, Brent Renouf, John Butcher, Mason Shaw.
Richmond - Matt Arnot, Tom Derickx, Brad Helbig, Dylan Grimes, Chris Knights, Jake King.
St Kilda - Jay Lever, Brodie Murdoch, Lewis Pierce, Josh Saunders, Adam Schneider, Tom Simpkin, Rhys Stanley, Jimmy Webster, Spencer White.
Sydney Swans - Craig Bird, Alex Brown, Harry Cunningham, Matthew Dick, Jed Lamb, Jordan Lockyer, Harrison Marsh, Martin Mattner, Tim Membrey, Mitch Morton, Shane Mumford, Nick Smith, Dean Towers, Tommy Walsh.
Western Bulldogs - Dylan Addison, Shaun Higgins, Nathan Hrovat, Will Minson, Fletcher Roberts, Jake Stringer