The Black Cats are currently 18th in the table and four points from safety with just six games left of the season.
Sunday saw them defeated by league leaders Leicester City, as slack defending saw Jamie Vardy open the scoring and then add a second late on in the 2-0 win.
It is not the first time they have been let down by the defence this season, and Yedlin says they must focus on keeping clean sheets between now and the campaign's conclusion in their efforts to avoid the drop.
“We have to stay tight and focused at the back; if you don’t concede goals you can’t lose so that needs to be the main focus,” he told safc.com.
“It’s a good sign that we’re creating chances but ultimately the next step is to finish them, so if we can start doing that we will start winning games. We have to look past this game and think about what we can do better.”
While the defence is an issue, a bigger concern will surely be the lack of goals in the side also.
Jermain Defoe is their highest goalscorer this season, and has been in impressive form in general, but has struggled to find the back of the net in recent weeks.
In that time they have struggled to score the goals needed to help them avoid relegation, and will need to find an answer to the problem quickly if they are to avoid the drop.