Ireland centre Bundee Aki believes losing his former Connacht teammate for key games against Wales, and possibly the rest of the Six Nations, will be a big blow to Joe Schmidt's side.
Henshaw left Ireland's 56-19 victory over Italy with his arm in a sling after injuring himself while scoring his second try of the game on Saturday.
While Joe Schmidt refuses to rule out Henshaw, if he can't recover to face Wales, there is no doubting his absence would leave a big hole in the centre of the Irish midfield.
"If he's not there for the next couple of weeks it would be a big loss," Aki said. "He's a big leader in the backline, but whoever steps up I'm sure will do a great job."
Aki scored his first try for Ireland, but insisted he had to park it, as he wasn't getting carried away with the impressive strength-in-depth available to Schmidt.
"In the beginning I was just happy to get over the line, to be able to help out the boys and get the score on the board was a bonus," Aki added. "To get my first try for this team was something special.
"As you can see in our team there's a lot of quality players, you can't take anything for granted. So you've got to keep going, keep playing and make sure you keep improving and making sure you're putting your hand up to fight for that spot again. You're never stamped into a team. It's all about just doing your job properly."
He needed to adjust when Keith Earls switched to centre, when Henshaw went off, but it didn't take him long to link up well with his new centre partnership.
"He's a world-class player, with the experience he has. I felt real comfortable with how he was playing, and that's the same thing Robbie [Henshaw] would do for me.
"I feel really comfortable with him on the outside, and Johnny on the inside, and it's the same with Earlsy. You can only feed off that experience and enthusiasm."