The 22-year old Newcastle-born centre-back is out of contract at the end of the season and is being linked with a shift to England next summer but McCall feels it would be better for his development to remain at Fir Park for the time being.
"I know he is enjoying himself here and he needs to look at the bigger picture too. His agent will be saying it's time to move on but I don't think it is yet," McCall told the Sunday Mail.
"I spoke to Shaun in the close season and told him I felt there is still some development in him.
"Obviously I want to keep him but Motherwell is a selling club and if he keeps improving there will come a stage when he is sold on.
"But we want him to sign this extended deal."
"Tom Hateley was three or four months without a club. Steve Jennings has only just signed for Tranmere.
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