It was revealed earlier this week that the former Republic of Ireland star served a six-week suspension for testing positive for cocaine during an off-season sweep by the Football Association in 2018.
Murphy apologised for an “isolated incident” which occurred in the off-season, claiming he had made a “bad decision while on a night out.”
And his manager, who is likely to name Murphy in the squad to face Peterborough United later today, does not expect the player to allow the headlines to have a negative impact on his game.
“He is an experienced player and I don’t expect this to have any bearing on him,” he told The Bolton News. “We all make mistakes and, for me, the fact this has come out now has more of an impact on his family than on Daryl himself.
“Over the course of a long career he has been an unbelievable mentor, performer, international calibre footballer – and I’m not sure at this point in time whether it was much of a story, anyway.
“I don’t condone it in any way, shape or form and I have had a chat with Daryl and he has been remorseful. But do I expect any impact on his performance? Not at all.
“He has served his sentence, done the education, and his performance levels for Bolton have been really good since he signed here. I wouldn’t expect that to alter because I think his mentality is very strong.
“He has made his apologies for something that happened in 2018 when he was at Forest so at Bolton we move on.”
A statement released earlier this week by Bolton read: “We are aware of the events which took place prior to Daryl’s arrival at the club.
“Daryl served a suspension and has expressed regret over the incident, which occurred out of competition.
“Daryl is a valued member of the first-team squad and the club will be making no further comment on this matter.”