Sir Alex Ferguson expects new Manchester United signing Alexander Buttner to challenge Patrice Evra for the left-back spot in his side.
United confirmed the signing of 23-year-old left-back Buttner from Vitesse Arnhem on a five-year deal earlier this week.
The defender will provide cover for Evra, who has been at Old Trafford since 2006.
And manager Ferguson believes the Dutchman will give the 31-year-old competition for the spot.
"We've been monitoring Alexander for a while," said the Scot.
"He's a straightforward attacking, quick full-back who will be a terrific addition to our squad.
"Patrice is in his 30s now, although he is still a fit lad. Alex gives us a good back-up and a good challenge for that position."
Buttner believes he can take lessons from Evra, who has made over 200 appearances for United during his time at the club.
He said: "I feel good. It's a dream for me to play for a big club like Manchester United. I can't wait to play for the team and let people see what I can do.
"I know I have to wait for my chance. I can learn so much from Patrice and I cannot wait to play with him. It's a nice club and everyone has helped me settle in."