Last season, in the slipstream of Robin van Persie, came the relatively unheralded capture of Dutch full-back Buttner, who has provided the competition that allowed Evra to rediscover the form of his early days at Old Trafford.
"Alex is doing well," he said.
"He needs to keep going. He needs to challenge me next year.
"I like the challenge. Maybe it is because he signed that I scored four goals and had six assists.
"It is good to have a challenge."