Garner has played a key part in Preston's rise
Latics boss Gary Caldwell, a former Celtic player, reportedly sent scouts to watch the 28-year-old ahead of a possible £1 million bid.
However, Rangers could pose a threat to the Scot's hopes, with manager Mark Warburton reiterating his desire to add another striker on Sunday (Daily Record).
Garner played 41 times for Preston in last season's Championship, scoring six goals and making another eight.
Garner scores against first club Blackburn Rovers last season
However, the Lilywhites have already signed Simon Makienok and Callum Robinson this summer, taking their tally of recognised strikers to seven.
Giant Dane Makienok is one of two attacking signings at Deepdale
And the pair's arrival could lead to Garner's exit, two years before his contract is due to expire.
The powerful front man, who was a teammate of new Ibrox recruit Lee Hodson at Watford, would bring a different dimension to Rangers' attack.
5ft 10 Garner is a proficient target man
However, Wigan are also in need of reinforcements having allowed Billy McKay to join Oldham Athletic on loan, leaving just Will Grigg, Craig Davies and Sanmi Odelusi as recognised strikers.