On Tuesday, Ken Rosenthal of The Athletic reported the D-backs remain the "most persistent" potential suitor for the O's slugger.
The New York Yankees and Boston Red Sox are among the other possible landing spots, but general manager Dan Duquette convincing team owner Peter Angelos to trade a major asset to an AL East division rival "likely would be difficult," per Rosenthal.
Machado saw his baseline numbers drop last season with a .259/.310/.471 triple-slash line. He still hit 33 home runs, however, marking the third straight year he topped 30 homers.
The 25-year-old Florida native can become a free agent after the 2018 campaign. Sources told Rosenthal last month he's interested in making a full-time move to shortstop, which would bolster his value on the open market, after spending most of his major league career at third base.
Machado hasn't talked about his impending free agency much in public since telling reporters last April he tries to "live in the moment:"
"Those are things that I would like to keep to myself and keep on my side. It keeps me going throughout every day and keeps me motivated to come out here and play baseball and play for a team, play for an organization like I am here and obviously you're representing the name across your chest and the name across the back of your jersey as well because that's who you resemble and those are things that are going to take you a long way."
His trade value isn't nearly as high if he won't consider a contract extension with the acquiring club, at which point he's merely a one-year rental.
In Arizona, Machado would likely be granted his wish of playing shortstop with Jake Lamb at third and Ketel Marte shifting to second, allowing the versatile Chris Owings to play a utility role.