"Phil is a good friend of mine," Henderson told SPORT. "I think he's an exceptional footballer, he has it all, he has a great attitude and he loves football.
"So, of course, for me, he would be welcome back, but it doesn't depend on me. It's probably best to ask the manager that. The guys adore him, so if you ask any of them, I am sure they would say they would love to have him back.
"But I think his time here has passed, he's moved and I hope that in the near future we see the same Phil that we saw here."
The midfielder added: "I thought that it was going to be a big loss for us, it would be for any team.
"But I felt it was a moment to take a step forward. The guys lifted their performances and we fixed things without him quite well."