The 29-year-old started out in the third tier with Carlisle but failed to score during a handful of appearances over two seasons from 2009-2011.
The striker then decided to forge a career in non-league football, turning out for several clubs and finding the net regularly.
A spell with Motherwell in the Scottish Premiership then came before he moved to Exeter in League Two – scoring 29 times over the last two seasons.
Now, Bowman has come full circle and is back to ply his trade in League One and boss Cotterill says the forward is aware he must prove the doubters wrong.
“I think he’d probably say he’s got to try to prove himself at League One level, we know that and he knows that,” Cotterill said.
“He’s a very humble boy, a very good boy, I think he deserves the opportunity.
“He comes into our pay structure, the fee for him was nominal in today’s market, he’s come in and done very well in training.
“In the two games he’s had he occupied defences, he’s an honest lad, which is what we wanted.
“He will be the first one to say in the games he’s had that Tom (Bloxham) did well with him the other night before his knock. He was very unlucky to have a goal disallowed, young Tom. And Dan Udoh I think has come back and looked incredibly sharp this year, which I’m really, really pleased about.”