Negotiations between the clubs had threatened to drag on, holding up other deals, but Essendon got involved in a pick swap that helped facilitate the only official trade lodged with the league on Wednesday.

The Cats will receive selections 14, 24 and 37 in this year's draft and the Eagles' first-round pick in the 2020 draft in return for Kelly, Geelong's pick 57 this year and a third-round selection in 2020.

The Bombers dropped back five spots in the third round but moved up from No.37 to No.33 in the second in a key pick swap that helped the first transaction of this year's trade period get over the line.

"The selections we have secured will give us the best opportunity to add high-end talent to our list in the upcoming national draft," Cats recruiting manager Stephen Wells said.

"We thank Tim for his two years with us and wish him well in the future, both in his football career and his family.

"Tim was obviously an exceptional player for us, but we are excited by the possibilities the draft picks we have secured offer us."

Kelly joined Geelong as a 23-year-old in the second round of the 2017 draft and went on to play 48 games in two stellar seasons where he finished runner-up in the best-and-fairest count in both years.

The prolific onballer was also named in this year's All-Australian team and finished fifth in the Brownlow Medal count.

Kelly's attempt to move his young family back to his native Western Australia last year came up short when the Eagles and Cats couldn't agree on a trade.

Despite Geelong's best efforts to provide the support he required, Kelly declined to sign a contract extension and handed in a trade request after the Cats' season ended in a preliminary final loss to Richmond.

While no other trades were completed on Wednesday, GWS warned Hawthorn they won't give away former No.1 draft pick Jonathon Patton cheaply.

Fellow top draft pick Tom Scully switched from the Giants to the Hawks during last year's trade period for a lowly fourth-round draft pick because of doubts over a serious ankle injury and with GWS keen to offload his salary.

After three knee reconstructions in eight years, Patton has declared he is keen for a fresh start under Alastair Clarkson, but GWS list manager Jason McCartney wants fair value in return.

"There's been a lot of discussion going back to last year and Tom Scully but this is a completely different situation," McCartney told AFL Trade Radio.

"We'll work closely to help facilitate what Jon wants but we do want to make sure that we get something back that's going to be worthwhile that we can use as part of our strategy going forward."

Hawthorn currently hold picks 11, 30, 50, 87 and 92 at November's national draft.

Adam Tomlinson has already departed GWS, the versatile tall joining Melbourne as a free agent.

The Giants received an end-of-second-round draft pick as compensation for his loss and will look to safeguard that pick by working a trade with Adelaide for Sam Jacobs instead of signing him as a free agent.

Australian Associated Press