The midfield duo, released by Wednesday this summer, are attracting the interest of Turner who wants the players as he bids for a promotion assault following their relegation, according to reports.
McMahon was given his full Owls debut under Turner while Hamshaw shone for the former Owls goalkeeper before an injury against Nottingham Forest on Boxing Day 2002 put him out of action for more than a year.
Meanwhile, Wednesday have had to let many supporters down who were wanting to buy the new black away kit this Friday.
The arrival of the new Diadora shirt, which replaces last season's silver shirt as the second choice strip, has run into problems.
Apparently the non-delivery of the kit is Diadora's fault and the club are hoping to rectify the situation as soon as possible although another launch date has not been released.
The new home shirt, which has so far received mixed reviews from fans, will be available on the 22nd June.