Sunderland manager Dick Advocaat admitted he still doesn't know much about on-loan defender DeAndre Yedlin, but said his pace is "superb" and feels the United States national team player will help add depth to the Black Cats.
Yedlin moved from Major League Soccer's Seattle Sounders to Tottenham Hotspur in the Premier League in January, but he's never cracked the lineup for Spurs.
The 22-year-old was part of a deadline day loan deal from Tottenham to Sunderland, where he is expected to get more chances to play.
Advocaat told the Sunderland Echo: "I don't know enough about him yet, to be honest.
"I've seen the videos of him and we saw him against Holland, when he did really well when he came on. But you can only see in training what he can bring and if he is better than the others.
"He only got here on Friday, so we need to work with him more."
Sunderland lost 1-0 to Tottenham on Sunday. Prior to that, Yedlin trained twice with his new club and also participated in a light training session on Monday. His future as part of Sunderland's regular XI remains to be seen.
"He will definitely strengthen our options at full-back," Advocaat said. "He's really quick and played for the national team last week more as a right-winger, than a full-back.
"But his pace is superb. It's all about balance with the full-backs, between going forwards staying back."
Sunderland travel to Bournemouth Saturday for their next Premier League match.