Roeder feels Carroll can still make it at Anfield.
"At his best Andy is virtually unplayable," Roeder told the Guardian. "I played him against John Terry and Sol Campbell in games with Chelsea and Portsmouth and neither could get near Andy in the air."
Roeder found Carroll consistently receptive to training ground advice but believes he needs to work hard on improving his right foot, movement outside the box, possession retention and first touch.
"If I were Andy I'd get DVDs of Michael Owen, look at his game outside the area and study how he does the simple things wonderfully well," Roeder says.