The defender played forty minutes for the Sky Blues against Everton yesterday and Coleman told the CT: "He had his time at Sheffield Wednesday and is out of contract now.
"Marcus has had a little problem with an injury behind his knee and I wasn't sure if he would finish 90 minutes and I was right. But even if he was fit we need someone in that area to compete as a natural full-back.
"Peter has come in and he was tired because he played 90 minutes for Southend on Friday night, but he acquitted himself very well and we are just having a look at each other, so there is nothing concrete in it."