Long was withdrawn at half time in the Tigers' 3-0 defeat to Arsenal on Sunday while Aluko missed the game entirely, and now both players are unlikely to feature against Fulham at Craven Cottage on Saturday.
Bruce told reporters: "Long's got a calf injury. We'll see how he is but he's got a whack to the back of his calf. He'll be touch and go for the weekend, I would have thought.
"Sone Aluko unfortunately nicked a hamstring on Thursday. It's unfortunate because we were just seeing Sone again. It's getting a bit too often with Sone, we get him up to speed and unfortunately he breaks down again and that's a disappointment."
Hull are 14th in the Premier League, six points clear of the relegation zone.