Saints paid Hull KR a £60,000 transfer fee for 30-year-old playmaker Burns, who is set to partner ex-Penrith Panths team-mate Luke Walsh, who is closing in on a return from a broken leg, in the halves.
Both are expected to feature in the pre-season game with neighbours Widnes Vikings on Sunday.
Cunningham said: “They’ve gone really well. They’ve had a really good pre-season both of them, they’ve trained hard, are very good athletes and very smart.
“I knew both of them were very good players and I knew they were good athletes it was just how they was as people, which you worry about, but they’ve come in and they’re just both good guys.
“We did our homework before we signed them and everyone was saying they were good people but you’re still worried that they come in, they integrate well and they fit into the squad.
“They’ve adapted to the way we play rugby league, they enjoy it and they want to win, the same as everybody else.”