Doncaster RLFC maintained their early-season Betfred League One promotion challenge with a 44-18 win at home to Coventry Bears.
But they could have paid a high price with utility star Kieran Cross looking to have sustained a serious shoulder injury after falling awkwardly in the second half.
Both stand-off Jordan Howden (dead leg) and prop Russ Spiers (knee) also came off in the second half and could be doubtful for Sunday’s Coral Challenge Cup tie against Batley Bulldogs.
“Kieran went for a scan after the game so we’ll see what that tells us but it’s not looking great at the moment,” said Horne. “We’ll have a better idea of the injury situation in midweek.”
Despite scoring an early try the Dons only led 16-12 at the break.
“We spoke about completing our sets and building some pressure and we probably didn’t do that at times in the first half,” said Horne.
“They scored a couple of good tries and were good value for their 12-4 lead at that stage. They are a tidy side and they’ve come a long way over the last couple of years.
“But I thought we did a really good job on them in the second half. We again spoke about building pressure and being patient during the interval and we were.
“You can’t score off every move and we have to learn that. You have to build pressure.
“Even when we made a break we didn’t throw out risky passes or kick the ball as we have been doing.”
The game saw two Hull FC players make their Doncaster debuts as part of the dual-registration arrangements and both pleased Horne.
“I though Kieran (Buchanan) was solid at full-back and didn’t do anything wrong and I thought Jack (Brown) was outstanding in the forwards,” said Horne.
“He won ground every time he carried and defended well.”