Bruce has now signed 11 players over the close season, the latest being James McClean from Derry City.
The Black cats finished 10th last year, but with the injection of quality provided by their new signings, they will be expecting a better return.
Turner picked up a couple of knocks over pre-season but has now shaken them off and is pressing his claims for a first-team place against Liverpool on Saturday.
"There's huge competition throughout the whole team, which is a good thing. It helps individuals to perform better in order to keep their place in the team.
"Everyone's pleased pre-season's finished now - it dragged on a bit because we just want to get cracking with the Premier League.
"I've had a couple of niggles in pre-season which has been disappointing, but I've featured in most training sessions and only missed a couple of games.
"Personally I feel fit and just want to get going now, like the rest of the boys."
The former Hull stopper admits a trip to Anfield represents a tough start to the season against Kenny Dalglish's revamped team.
"It's a tough start but Anfield is a tricky place to go at any point in the season," he told the club's official website.
"We know all about Liverpool and we know it'll be a tough game."