The Brazilian has struggled for form since leaving the Premier League, but the Englishman believes Lampard can get Coutinho back to his brilliant best.
Coutinho left Liverpool for La Liga giants Barcelona in January 2018, after an impressive five years in England.
The 27-year-old’s dream to play at Camp Nou did not turn out to be what he hoped for, as he has failed to live up to his known standard.
Coutinho was loaned out to Bayern Munich last summer, with the Germans having the option to buy upon the deal's conclusion.
But it is reported that the Bundesliga champions are unlikely to sign the former Inter Milan man, a decision which has sparked speculations over Coutinho’s possible return to England.
Johnson believes his former Liverpool team-mate is an exceptional player judging from his CV and has entreated the Blues to secure his services.
“Obviously you look on paper at his CV, at the clubs he’s been at, and it’s unbelievable,” the 35-year-old told talkSPORT. “You don’t get to those clubs without an enormous amount of ability.”
“He’s not reached the heights he’s capable of since he’s left Liverpool and it’s hard to put your finger on why.”
“I know he’s a quiet guy, a very nice lad, but he’s got a bit of fight about him on the pitch, he won't be pushed around.”
“At Barca you go there and there’s a superstar in every corner you look, and maybe he just blended in a little bit rather than being the key man.”
“I just think he needs to be made to feel a bit special; he needs an arm around him, and I think he’d get that at Chelsea.”
Johnson added: “I think he’s just a bit cautious when he meets new people and it takes him a bit of time to come out of his shell.”
“That’s why I guess when he walks into a new dressing room it will take a bit of time for the lads to get to know him, but he’s a really nice lad.”
“I think it would be great for him and his family to be in London and Lamps could be the man that puts his arm around him and makes him feel he is a key part of their plans, and I think that could force the best out of him.
“There is no doubt about it, the boy can play. He’s a proper footballer. “
“He’s not the quickest lad and he’s clearly not the biggest lad, but his brain, his sharpness and speed of his football brain... he just picks that pass and he’s got that technique and perfect mobility in short spaces that opens up defences, and that’s something you can’t teach.
“And if Chelsea get the chance to sign him, they should be signing him. He’s unbelievable.”
