Bayless leaves with ankle sprain
Bayless played 21 minutes in the Blazers' 98-95 loss to the Celtics, recording 12 points and four assists before suffering the injury.
Roy has been ruled out for Portland's next four games after re-aggravating a right hamstring injury against the Philadelphia 76ers on Wednesday night.
Bayless is averaging 8.8 points and 2.3 assists for the year.
Information from the Associated Press was used in this report
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