A combination of Van Persie's lack of pre-season training and Rooney's gashed thigh meant the pair did not start in the same team together until the Champions League trip to Cluj.
Even then Rooney was in a deep-lying midfield role, as he was at Newcastle six days later.
Something must have been going right though because United won both games, and they maintained that sequence at Old Trafford yesterday [Saturday] when Rooney was pushed further forward against Stoke.
Even better as far as Sir Alex Ferguson is concerned, Rooney and Van Persie both found the net.
That the pair were also responsible for three of the four assists just proves what potential there is from United's new strike force.
"We are definitely getting more of an understanding," Van Persie said.
"We like to play together and work well together.
"It is only the second or third time we have played in this formation but offensively and defensively, we help each other out."
The ability of both players to operate as the spearhead of United's attack, or drop deep, or push out wide, provides a conundrum it will be difficult for any defence to solve.
Danny Welbeck is also capable of making a significant contribution and with Javier Hernandez, Nani, Shinji Kagawa and Ashley Young also offering a threat, it is little wonder Ferguson currently views attack as the best form of defence.
"We do look exciting going forward," added the Dutchman.
"We can score all sorts of goals from many different angles.
"That is a good sign and should be a real weapon for us as the season goes on."
If that is true, then concerns about the defensive side of United's game are also valid.
The return of Chris Smalling clearly cannot come quickly enough to take some pressure off Jonny Evans and Rio Ferdinand, whose status at United is open to question following yesterday's [Saturday] refusal to wear a t-shirt highlighting Kick It Out's anti-racism campaign.
It had been anticipated Smalling would be available to face Stoke, only for Ferguson to reveal on Friday the former Fulham man still was not quite right after recovering from a broken metatarsal.
However, with Tuesday's tricky Champions League encounter with Braga being followed by two games at Chelsea, one against Arsenal before the European return with the progressive Portuguese outfit, Smalling's presence is required as United look for some solidity.
Rooney's own goal, the prelude to him reaching 200 club goals in the right net, meant United have now fallen behind in seven of their 11 matches so far this season.
It is a run that has already cost them valuable points against Everton and Tottenham this term, and if it continues over the next fortnight, could have a significant impact on this season's trophy quest.
"It has happened too often," said Van Persie.
"We have to work on it because we can only do better."
Kagawa, Tom Cleverley and Ryan Giggs are among those who are pencilled in to face Braga, while a change in goal is also anticipated given Ferguson's recent policy of rotating David de Gea and Anders Lindegaard.
Rooney, as always, will want to be involved, especially now he has broken his duck for United this term, and reached such a significant personal landmark.
"I didn't know until afterwards," he said of his 200 haul. "I am delighted with that.
"As a forward you want to score and I am delighted to get off the mark.
"Hopefully there is more to come but if I can keep putting good performances in and playing well and working with the team, I will be happy with that."