The 24-year-old was left fighting for his life after collapsing during the first half of Bolton's FA Cup quarter-final at Tottenham on March 17, which was subsequently abandoned.
Kinshasa-born Muamba's heart stopped for 78 minutes as medics battled to keep him alive at the stadium and then in the London Chest Hospital, but he has since made rapid progress and was discharged on Monday.
He is now spending time with fiancee Shauna and son Joshua as he continues his recovery.
Coyle, who spoke to Muamba on Wednesday, said Thursday "I'd come in from training and Shauna sent me a message: 'There's somebody who'd like to speak to you.' And when I spoke to him, you can always tell from the sound of somebody's voice and he sounded in a good place.
"It was great to hear from him and he sounded terrific. Of course, that's a huge boost given where he's come from.
"We've all seen the sad events in Italy," added Coyle in a reference to the death on Saturday of Livorno midfielder Piermario Morosini after he suffered a heart attack on the pitch.
While Muamba's return to health is the priority for both himself and his club, Scottish manager Coyle said he could yet play football again.
"I understand, because of the interest, that everybody thinks he's released from hospital so that's it, he's singing and dancing down the street, but people have got to understand there's room for continued improvement," Coyle, whose side are battling to avoid relegation from the Premier League, said.
"But knowing Fabrice and how much of a battler he is, it wouldn't surprise me if he comes back. But I've got to stress he still needs that time with his family unit.
"His little lad hadn't been able to see him for a period so it's important we give them that time to be together.
"God willing, if he ever comes back to play at the level he's played before then, of course, that will be a huge boost to everybody."
Source: AFP
Source: AFP