Martin said, "Being brutally honest, the people it affects the most are me and his coaching staff because he brought us into the club."
Martin continued: "I don't think it's affected the players. Jason is a great guy, I speak to him a lot. I have had the most conversations with him here. I don't think it's affected the way we work or the results.
"It has not affected the process we are working on. But, of course, he is a good person and you never want to see good people walk out of the building."
He added: "Manchester United have a job to get the guy that they want. If it ends up happening then Jason goes with our best wishes. He has played such a big role in changing the culture here.
"What he does has enabled us to be the leaders we want to be. He has been so supportive. Hopefully, we did a good job for him.
"There is still a lot of stuff legally that needs to be worked through by both clubs. If he ends up going, which looks likely, I wish him nothing but the best.
"It's Manchester United, he moved down here from there. I'm sure the relationship will continue beyond this. He is a good guy and we will see what happens."