Jelavic and Long have scored three goals apiece since arriving from Everton and West Brom respectively.
Long was on target against his former club on Saturday as Hull pulled eight points clear of the relegation zone with a 2-0 home win.
There could have been a goal for Jelavic earlier in the game, but the Croatian missed a penalty, which had been won by Long, and was grateful to see Liam Rosenior spare his blushes by following up to open the scoring.
Bruce was full of praise for his front pairing, citing their arrivals as a turning point in Hull's season.
"The two strikers, in my opinion, we gave the whole club a lift by bringing them in," he said.
"They've both made a difference to us because we didn't play well (against West Brom).
"But we've got a bit of quality up the top end of the pitch to get you something.
"With those two up front, when you don't play well they can maybe create something for you and they're always going to be a handful with the attitude both of them have got."
Although Bruce admitted Hull had been far from their best on Saturday, he was pleased with the determination his side showed in grinding out a result.
"We didn't play well but there was a resilience and an attitude that once we got the break and got the goal we'd see it through," he said.
"That was pretty evident for everybody to see. At the moment we're doing okay and I hope that continues."
