Phil Jagielka has hailed the development of Jack Rodwell, but claims he is not the finished article yet.
The Everton youngster has enhanced his reputation again this season, with various reports suggesting he is a summer transfer target for Manchester United.
A product of the Goodison Park academy system, he is regarded as one of England's hottest prospects.
At just 20 years of age, Rodwell is already an accomplished Premier League performer and England U21 international.
He has, however, struggled with niggling knocks at times and Toffees team-mate Jagielka believes the classy midfielder cannot be judged until he has taken part in a full campaign.
"Obviously it's nice to see Jack back and, hopefully, he will stay fit for the last four or five games," said the Everton centre-half.
"It's hard to say how good he will be, because although he's been in and around the first team for three years, he needs to play 30 or 40 games a season before we can answer it.
"The potential he's got is frightening and we have no doubts he will be that good. But you can't rate him as highly as you'd like until he's played a whole season. He knows that as well.
"He was desperate to play more this season, but had a few injuries, maybe came back a bit early, and it's all about form.
"You can have it for one or two games, but you need it for five to ten.
"We probably do miss him in midfield when he's not there because you can see he's so comfortable on the ball, running with it and with the range of passing he brings to the team.
"So the answer to how good he is, is that yes, he's good, but as to how good he will be only time will tell."