Harper, 22, has completed a medical test with the Bulldogs and is believed to be open-minded to a fresh start after struggling over the past two seasons with form and injury.
 
The forward was the No.27 pick in the 2010 national draft and after his first two seasons at Arden Street was considered one of the Roos' brightest young prospects.
 
North still faces stiff competition from Essendon to win Cooney's commitment.
 
The Roos' offer to the Bulldogs could also include an exchange of draft picks, the highest being their second-round pick, No.36.
 
The Bombers' hand could also be strengthened with Port Adelaide upping its offer for Ryder to include pick No.37 on top of pick No.17.
 
However, even if the Ryder deal is done before Thursday's deadline, it might not be done in time for the Bombers to put in an improved bid for Cooney.
 
The Kangaroos have thrown Harper into the mix as a possible sweetener to add value to pick 36, which it has available to trade.
 
If Essendon agrees to trade Ryder for picks 17 and 37, which Port Adelaide put on the table on Tuesday in an attempt to seal the deal, it could use pick No.37 to secure Cooney.
 
Ryder, of course, still has the option of heading to the grievance Tribunal if a deal is not done.
 
Essendon will attempt to broker a deal with Greater Western Sydney for Jonathan Giles after the ruckman nominated the Bombers as his new preferred club on Tuesday morning.
 
The Bombers beat off keen interest from Adelaide to win Giles' commitment for the next two seasons, and are likely to centre their offer for Giles around their third-round pick, No.53.
 
Adelaide have shown some interest in another ruckman from GWS, the Victorian-born Tom Downie, while Hawthorn's Luke Lowden looks increasingly likely to stay at the Hawks.
 
Mitch Hallahan is considering an offer from the Gold Coast however the Suns and the Hawks will need to sort out an appropriate deal before he becomes certain of heading north. Hallahan has talent but has lacked opportunities at the back-to-back premiers.
 
The Western Bulldogs are also in discussions to secure Sydney Swans half-back Shane Biggs, who appears unlikely to remain at the Swans.
 
The Swans have committed to three Academy players in the upcoming NAB AFL Draft, as well as rookies Jake Lloyd and Xavier Richards, who have been promoted to the senior list. 
  
It is understood there is insufficient cap space to also promote Biggs to a 38-man primary list, but he is a player the Swans would expect compensation for losing.
 
Essendon is also understood to be pursuing the 23-year-old, who played three games in 2014 and two finals in 2013.
 
If Biggs does not find a home by Thursday's 2pm trade deadline, he would be expected to move freely as a delisted free agent, given the Swans are unable to promote him and he can't be retained as a rookie for a fourth season.   
 
Collingwood threw pick No.67 the Brisbane Lions' way to keep Dayne Beams company.
 
In return it will receive pick No.5, 25 and young midfielder Jack Crisp.
 
With that deal in place the Magpies are likely to use No.25 to recruit Levi Greenwood from North Melbourne.
 
The Beams deal has held up the three-way trade that would see Heritier Lumumba join Melbourne, Mitch Clark join Geelong and Travis Varcoe join Collingwood, as it impacted on the deal offered to Varcoe.
 
However with Beams secured, the Cats and the Demons have their fingers crossed that paperwork might be lodged on Wednesday.
 
Geelong is considering using its pick No.21 for St Kilda forward Rhys Stanley, while Melbourne is trying to work through a fair trade for Sam Frost, a key defender from Greater Western Sydney.
 
If a trade is not finalised for Frost then the Demons are likely to use the pre-season draft to secure him.

Meanwhile Geelong football manager Neil Balme told SEN radio station Taylor Hunt would not be offered a place on the Cats' list in 2015.
 
Carlton remains confident of finalising a trade for Giants Kristian Jaksch and Mark Whiley with just a few minor details of the deal to be finalised.
 
The Blues will pass on pick No.7 to the Giants in the trade, but will receive No.19 back from GWS.
 
Carlton remains committed to trading for Bulldogs key forward Liam Jones, but talks between the clubs have stalled and the Blues could end up securing him through the pre-season draft.
 
The Blues also remain interested in Bulldogs midfielder Jason Tutt, but are no closer to agreeing to a trade.
 
One week after requesting a trade in search of more opportunities, young Essendon midfielder Elliott Kavanagh appears likely to serve the final year of his contract with the Bombers.
 
Kavanagh, who was recruited with pick No.19 in the 2011 NAB AFL Draft, announced through his management last week that he was exploring his options after seven games in three seasons.