Alan Smith has revealed that he received a letter of thanks from Sir Alex Ferguson for the part he played in Manchester United's success.
Smith joined Newcastle this summer after Ferguson admitted he could no longer be guaranteed regular football at Old Trafford.
But Ferguson has shown his appreciation for Smith and conceded it was a difficult decision to let the player go.
Smith, who battled back from injury last season to help United claim the Premier League title, told The Sun: "I must have done something right when I was there for the manager to take the time to send me a message like that.
"I was really pleased to get the letter. He thanked me for my contribution to Manchester United and told me what a difficult decision it was to sell me.
"I understand that. There are no hard feelings."
Smith is thrilled to have joined The Magpies, who are unbeaten so far this season, and is looking for his new side to challenge for a place in the top four.
"I've been lucky to move from one big club to another and, hopefully, I can help bring some silverware to Newcastle after so many years without a trophy," he explained.
"I'm not saying we will win the league but it is as open as I can remember. It is not going to be so easy for the top four to beat the rest.
"A lot of clubs have spent money and are aiming at the Champions League, which is good for the competition."
Smith has been included in the England squad for the Euro 2008 qualifiers against Israel and Russia, and is hoping to start after playing in the recent defeat to Germany.
But he accepts that Steve McClaren may view him as a useful option rather than an automatic starter, due to the fact that he can fill a number of different positions.
Smith said: "I want to play for England and help us qualify for those finals and I won't be happy if I'm left out. But the boss will do what he has to do.
"Perhaps the fact I can play in midfield and up front gets me into the squad, but maybe versatility counts against you when it comes to being in the team."