Cristiano Ronaldo has been Manchester United's "heartbeat", according to Usain Bolt, who says he understands the striker's recent criticism of the club.

Ronaldo has come under fire this week after conducting an explosive interview with Piers Morgan, in which he said he felt "betrayed" by United and had no respect for head coach Erik ten Hag.

While Ronaldo is preparing to appear at his fifth World Cup with Portugal, United have committed to taking "appropriate steps" against him.

Former United defender Gary Neville is among those to have urged the club to terminate Ronaldo's contract, but eight-time Olympic gold medallist Bolt – a keen Red Devils supporter – would be sad to see him go.

Questioned by Sky Sports regarding the five-time Ballon d'Or winner's future on Sunday, Bolt said: "Yeah, I'm sad to see him go, you know what I mean?

"It's Cristiano Ronaldo, he's been, as far as I can say, Manchester United's heartbeat. He's done so well for the club.

"For me, it's going to be stressful to see him go, but I understand what he's saying. I watched the interview, so I know what's going on."

Ronaldo top-scored for United with 24 goals in all competitions last season, but he has played a limited role since Ten Hag took charge ahead of the new campaign.

The 37-year-old has started just four Premier League games for United this term, hitting the net once, in a 2-1 victory at Everton last month.