Mich. Comp. Laws § 774.15

Sec. 15. If any of the jurors named in the venire fail to appear in court, or if there is a legal objection to a juror who appears, the municipal court shall supply the deficiency by directing any police officer of the city who is present and disinterested, to summon as a juror any of the bystanders or others who may be competent as jurors and against whom a cause of challenge does not appear.