Millen oversaw a scrappy, but vitally important, 1-0 victory at Hull to end his four-match spell at the helm on a positive note and has now handed the reins to Pulis.
The former Stoke manager has signed a two-and-a-half-year contract and will begin work with his new side above Sunderland on goal difference, a significant psychological boost for the start of his tenure.
The man who provided that lift, Millen, is uncertain how long his services will be required by the Pulis regime but is keen to remain at the club.
"I'd love to stay. I know Tony from previous clubs and I'd love to be in his plans," said Millen.
"I'm sure we'll sit down together and have discussions about a lot of things over the next few days.
"I've spoken to the chairman (Steve Parish), I'd like to stay and I've said that from day one.
"Tony needs to assess the group really quickly because we have a week now before our next game, which is a massive game for us.
"It's not like a new manager's come in in pre-season where you have weeks to work the group.
"He's got to work quickly and if I can work with him and help, I will."
Pulis was in the stands to witness Barry Bannan's 81st-minute winner at the KC Stadium and, speaking briefly as he left the ground, appeared to be grateful for the work done by Millen.
"Obviously I am very happy to be at the club and this result makes it a great start for me," he said.
"The first thing I would like to do is thank Keith for what he has done over the last few weeks.
"Personally it is terrific for me to come in on the back of a win."
There was also a vote of confidence from Parish, who added: "To be fair to Keith because he has done a cracking job. He has got us back to a way of playing we know and given Tony a really good platform to come in on."
Hull, who came up from the Championship with Palace last season but enjoyed a much stronger start to the campaign, had a dire day at the office.
They lost their unbeaten home record, conceded the winner after Palace lost Yannick Bolasie to a harsh red card and offered precious little goal threat until Liam Rosenior struck the post deep in injury-time.
The latter issue is one that will worry manager Steve Bruce most acutely, with the Tigers having scored just four times in six matches on home turf.
Two of those were Robbie Brady penalties, one a Carlos Cuellar own-goal and the other a Curtis Davies header from a corner.
"That's always going to be the issue," admitted Bruce.
"If you look at any bottom-half team in the Premier League the question is always going to be can you create enough and can you score a goal?
"Everybody will be well organised and disciplined, everybody is difficult to play against, difficult to beat.
"The top end of the pitch is always the most difficult. The loss of Sone Aluko and Brady, over the last few weeks, means we've lost that bit of edge.
"Certainly that's the case with Aluko. But that's the Premier League - it's very, very difficult."
Although well short of their best, Bruce felt Hull might have escaped with a goalless draw had they not had a meltdown late in the day.
"We made a mistake defensively," he added.
"It was our throw. Elmohamady was in the wrong position, Maynor Figueroa should have done better, Rosenior miskicked it...it's a catalogue of errors really.
"But we can't keep relying on the defenders, who have done well for us week in, week out.
"We need to create something and score a goal to give us that bit of ease that we want."
Source: PA
Source: PA