Lee Johnson admits he took a 'risky decision' by handing deadline day signing Ron-Thorben Hoffmann a baptism of fire against Accrington Stanley.
The on-loan Bayern Munich goalkeeper made his debut in English football at the Stadium of Light, and he looked nervy on a number of occasions when attempting to claim aerial balls inside his penalty area.
Johnson preferred the 22-year-old ahead of Lee Burge, who had recovered from injury and was included on the bench, and youngster Anthony Patterson, who had deputised for Burge in the last three games but found himself out of the matchday squad today.
"There were a couple of what I'd call rusty moments," Johnson admitted when asked about Hoffmann's performance in the 2-1 win against Accrington.
"There were a couple of aerial ones where he made bold decisions, which I like, but maybe just hasn't quite got his timing yet.
"It was a big decision and a risky one really, throwing him in.
"If he had made a mistake it would have been on me and not him, because he was playing behind two centre-halves he had never met before until the day before the game.
"But he was very good with his feet, and that played a big part in our build phase and we had two or three chances on the back of that.
"He did take two or three crosses and made one great save at the near post that was very important.
"We knew that Accrington were going to be a threat from set-plays and we are disappointed that we have conceded from one, but at the same time when it did get tricky to deal with because we hadn't managed to finish them off, we did get bodies in the way and make clearances."
While Hoffmann was thrust straight into the starting XI, his fellow deadline day arrival Leon Dajuku was not included in the squad - something Johnson had hinted at in the build-up to the game, when he said the on-loan Union Berlin winger was short of match fitness.
But while the 20-year-old missed out today, Johnson hopes he will be ready for next weekend's trip to Fleetwood Town.
Johnson said: "I made that decision pretty early and told him [Dajaku].
"He's looking really sharp over the last couple of day, but he is still way behind the other lads in terms that he has had no pre-season minutes, minimal training - or not at the tempo that we require - and there's a lot going on with his family coming across, and the need for visas and all that.
"To be able to work him hard and put him through that ten-day extensive hit, it was really important that we ruled this game out completely.
"If we'd put him on the bench, he might have to come on after a minute.
"I'm pretty sure that next week he will be available for selection."
Dan Neil gave Sunderland the lead against Accrington, before Michael Nottingham levelled on the half-hour.
Carl Winchester restored Sunderland's advantage just before the hour, and that goal proved enough to secure the Black Cats' fifth win in six league games at the start of the season and send them two points clear at the top of the League One table.
