The news intensifies speculation Motlop could be let go by Geelong after another lackluster season and could be offloaded to the Suns as part of the trade to bring Gary Ablett back to the Cats.
Motlop and McDonald were also accompanied by Suns list manager Scott Clayton as they spent two hours touring the training base.
“We have been told he spent time at the Gold Coast Suns this morning having interviews and a tour of the facilites there,” Barrett said on AFL Trade Radio.
“We know that Steven Motlop is a free agent but we also know there is still capacity around this trade period for him to be used as leverage potentially in that deal.”
The 26-year-old is also said to be close friends with Gold Coast co-captain Steven May.
The Suns announced last week Ablett has requested a trade back home to Geelong and the club is demanding a player in Geelong’s best 22 in return for Ablett.
Motlop played 23 games for the Cats this season, averaging 19.3 disposals and kicking 22 goals.