Ertl has not started a game for 10 months due to knee trouble but is on standby to return to the Blades side this afternoon.
The opposition may only play in Conference South but Ertl admits the FA Cup has a special place in his heart.
“Growing up in Austria, I used to love watching the FA Cup on television,” he said. “It was always my goal to come to England and play football, especially for the FA Cup.
“A couple of seasons ago, when I played for Crystal Palace against Aston Villa (in the fifth round), the game was broadcast in Germany and Austria and it was the first time my family had been able to watch me back home.
“That was a great experience and I even scored my first goal. It was a win-win situation and I would love to have another good run in the competition this season.”
Former Austria Vienna defender Ertl, 29, says the Blades will not underestimate today’s opponents, who won promotion last season and are in third round for the first time.
“For them, it is like an FA Cup final – but we have to treat the game as a final, too,” he said. “We should treat every game like that. Anything is possible in the FA Cup. Sometimes you get ‘David against Goliath’ and people like it when the lower league team beats a club higher up the table.
“But we will show Salisbury the deepest respect because a football game always consists of 11 v 11 and they are going to be right at it. We have to make sure we show commitment, good habits and our attitude is right. We are not in a position where can underestimate any team.”
Sailsbury player-manager Darrell Clarke is no stranger to Blades manager Danny Wilson but found first-team opportunites hard to come by when the pair were together at Hartlepool United.
Clarke, 34, was eventually released by Wilson but says there are no hard feelings.
“I’ve been ‘umming and ahhing’ but I think I’ll have a bit of banter with him on the day,” he said.