As Hayes is under 24 the Tykes are entitled to a transfer fee for the player, a cut of which will be owed to Scunthorpe as part of the deal which took him to Oakwell three years ago.
"Paul is one of the strikers we are looking at," confirmed Shrimpers assistant manager Paul Brush.
"We want a striker who can make runs in behind defences and Paul certainly comes into that category.
"We need someone up front who is different to what we already have because at times we were too predictable last season."