The former West Bromich Albion striker believes that he has struck up an immediate understanding with the Croatia international and says that he has settled into Hull well
Hull are currently 13th in the league following their 1-1 draw against Tottenham and Long, who scored the opener against Spurs, is aiming to improve the club's fortunes on the field.
"Hopefully myself and [Jelavic] can make a difference on the field and help the club climb the table," the Republic of Ireland international told reporters. "I can already sense an understanding there and it's exciting.
"Nikica is a very good player and easy to play with. The first thing we think about when we get the ball is where on the pitch the other one is.
"Although it's still early days, I think it can grow into something good. I was happy to score on Saturday [against Tottenham] and it was just disappointing it didn't lead to all three points because I thought we played well."
"I've settled in straight away," added the former West Bromich Albion striker
Meanwhile, Shay Given is hoping that he has done enough during his loan spell at Middlesbrough to attract potential suitors as his time at Riverside nears a conclusion.
The 37-year-old goalkeeper will not have his loan spell with Middlesbrough extended because Aston Villa were keen to have a "24-hour recall" clause, something that would not have been available in the event of an extension until the end of the season.
"I just hope there will be a few options for me," Given told reporters. "Hopefully this spell at Middlesbrough will have shown I still have a lot to offer."
He added: "Aston Villa wanted to have that 24-hour recall they have on the emergency loan in case something happened to Brad Guzan.
"Had they extended the loan until the end of the season they couldn’t call me back. That recall would have been scrapped.
"Villa didn't feel they could take that risk. They wanted somebody with experience as an option to call on.
"I could possibly go to another Championship club when I go back there, but I can't come back to Middlesbrough."