Long will face former club West Bromwich Albion today.
"West Brom's loss has certainly been our gain," he told the Hull Daily Mail.
"We took advantage of him coming to the end of his contract. He's had a really good start to his life here and quickly made himself popular with our supporters.
"I'm sure he'll be wanting to do well again and score against his old club, that's only natural, but I don't think he'll think he's got anything to prove.
"I know how popular Shane was with West Brom supporters.
"I don't think Shane Long's got anything to prove to them. They know he's an honest lad who always gave his best there."