The former Tottenham and Liverpool man was impressed with the South London club's replacements as they rallied to secure a last gasp point at home on Saturday.
Murphy, 41, emphasised the importance of the wider playing squad in the modern game and made the remarks that although Chelsea lack a prolific striker to match their rivals, they can still have success this season.
Writing in 'MailOnline' he said: ''Anyone who doubts it takes 14 players rather than 11 to be successful in Premier League matches should take a look at Chelsea's late rescue mission.
''Maurizio Sarri's side were in control for large parts of the game. Then they were messed up by United's equaliser when Marcos Alonso stayed down when I don't think he needed to — he would have blocked Martial's shot.
''But chasing the game at 2-1 down, the Chelsea boss was indebted to the quality of his substitutes, Pedro, Olivier Giroud and Ross Barkley, who got the equaliser. Their contribution was vital.
''Recent history tells you that Premier League champions normally have a 20-goal-a-season striker. Giroud did get 16 in the league one year for Arsenal and this team is better than that one.
''I like Morata, he's a clever player, but I think I'd give Giroud a run of games. You don't always need a free-scoring centre-forward, particularly if Hazard was going to get 20 or 25 this season, but it is still very important.''