Dave Jones guided the Owls to promotion last season but must now be feeling the pressure after a pointless September, and Saturday's result leaves Wednesday in the Championship relegation zone.
Jones made three changes from the draw with Burnley with Lewis Buxton, Miguel Llera and Rhys McCabe drafted in for Jermaine Johnson, Martin Taylor and Nejc Pecnik.
Steve Bruce also made three alterations as Liam Rosenior, Andy Dawson and Paul McKenna came in for Alex Bruce, Joe Dudgeon and Robert Koren and an injury crisis meant that the Tigers could only name six substitutes.
The home side should have taken the lead when some good work from Michail Antonio and Ross Barkley set up Chris O'Grady but the striker could only put his effort over the bar.
Antonio continued to be a threat and he tried to follow up his stunner in midweek as he cut in from the left and curled a shot but it brushed the outside of the post.
The Owls were starting to get on top and Llera thought he had given them the lead with a header but his effort was cleared off the line.
Both sides were playing well and it was the visitors who came close to taking the lead just before the break as McKenna hit a crisp volley which went just wide.
Ahmed Elmohamady set up Hull's best chance of the match so far as he found Stephen Quinn who was given too much space in the box but the former Sheffield United man fired wide.
The Tigers were bossing things but Antonio was providing some spark for Wednesday and there were loud appeals for a penalty as he was brought down by Dawson but referee Jon Moss was not convinced.
Sone Aluko was then presented with a golden opportunity as McKenna's ball cut open the Owls' defence but the former Rangers man missed the target when it looked easier to score.
The game went into a lull with both managers making changes to try and find a spark and it was Bruce who saw his substitution pay off as the visitors took the lead.
Mclean was brought on for Jay Simpson in the 75th minute and within two minutes he was on the scoresheet as some good build up play left him one-on-one with Chris Kirkland and he slotted a low shot home.
Wednesday went on the offensive and substitute Johnson did well with a shot from a narrow angle but Ben Amos was equal to it.
The Owls applied some late pressure but it was not enough as their wretched run of form continued.