Coleman admits Galloway has been 'wasting his time' on Wearside - but hopes the defender still has a part to play in their fight against relegation.
And Coleman has also expressed his curiosity at Everton not managing to agree a deal to send him elsewhere for the reminder of the campaign.
“Brendan is a lovely kid and he has been working hard but he has lacked game time," said Coleman. “He's here to get game time and he is not getting it.
“You don't want to waste the boy's time, it is a critical stage for him.
“We thought maybe Everton would want to take him back, maybe loan him out somewhere else – even in the division below – but that wasn't the case.
"So Brendan is still here, and he is a cracking boy. Who knows, we may need to call on him yet."