He joined on a short-term deal from the Championship part-timers earlier this season but has now made a permanent move for 2020.
Trout, 28, started his career with Wakefield Trinity but has spent the last four years in the second tier with Dewsbury and Sheffield Eagles.
Tony Smith gave him a chance with the Robins in August and he impressed with his performances as he helped them stave off the threat of relegation, persuading the coach to give him another crack.
“I remember when I first joined, at the back end of last season, I had said I didn’t think I would get the chance of playing Super League, so this opportunity is great for me once again,” said Trout.
“I got a lot of confidence from my displays and I really enjoyed my time with Rovers, so I am delighted to be back again.
“Tony has given me a massive boost of confidence. To get the call from somebody of his reputation for 2020 was great.
“He was a big reason in me making the move initially and jumping straight into the deep end, but I feel with a big pre-season under my belt I can become the best that I can be.”
Smith added: “After throwing himself in at the deep end without a Super League pre-season under his belt, Kyle has another chance with us in 2020. “Now he has got a full-time position and with a full off-season to prepare with us, he will be ready to take this opportunity.
“Kyle understands that this may be his last chance to re-establish himself as a Super League player.
“Once you leave a position such as the top level of the sport, you sometimes do not appreciate what you had. We are happy to give him that opportunity and he will take it.
“Kyle will play in the middle for us, whether it be at prop or at loose-forward. “He knows there is competition for places within the squad, so he must be at his best like everybody else.
“With a pre-season amongst the group, he will feel much more comfortable and know what is expected of him.”