The caretaker boss led the Eagles to a precious 1-0 win at Hull and believes the club are in the best possible hands after the former Stoke manager was announced as his successor
The caretaker manager fielded questions on the new manager's appointment, announced hours before Palace's crucial 1-0 win at Hull City, in the post-match press conference and is confident the club have chosen the right man after a protracted hunt for Ian Holloway's replacement.
Barry Bannan's goal gave the visiting South London side their first away win of the season but the name on everyone's lips was that of Pulis.
When quizzed on the Welshman's appointment, Millen told reporters: "I've said from the start that what I felt was needed was probably someone with experience at this level because the club haven't got experience.
"For me, Tony was top of the list and I'm delighted he has decided to come on board. I am sure he will be pleased to see the team today and the commitment to the club, it gives him something to work with."
While Millen admitted his delight and pride at winning his last game in charge of the Eagles, the temporary boss revealed both himself and Pulis decided it was in the club's interests to conceal news of his arrival as to retain a focus on the task in hand at the KC Stadium.
"I spoke to Tony on Friday and this morning and we felt it was really important that we stayed focused on what we've worked on the last two weeks for this game," said Millen.
"And I think if Tony had come in it might have distracted away from me being in charge and undermine me a little bit.
"It filtered through this morning to the players that Tony had signed and was taking over on Monday and from the meeting we had at the hotel it was: 'I'm in charge, continue with what we've worked on, the game plan and it worked out today."
Palace's protracted search for a new manager hardly improved their widely-perceived billing as favourites for the drop but Millen informed Pulis ahead of his decision to join the club that the club can definitely hold on to their Premier League status.
"That was one of the questions he [Pulis] asked me," Millen informed. 'What do you think of the group's mindset?' and I said to him I honestly believe these lads can stay up.
"If I felt they didn't then, as a group, you pick up on the vibes in training but there is a belief there that we've got a fighting chance.
"So I think Tony was pleased to hear that and if he can come in and add a bit of experience to the group of how to win games at this level, then we've got as good a chance as five or six teams in this league."