The time was right for Danny Welbeck to leave Manchester United
Louis van Gaal has claimed ahead of Manchester United's visit to Arsenal tonight that the sale of Danny Welbeck was justified because it enabled the club to bring in Radamel Falcao.
The Colombian, who has scored once and started only three Premier League games since his arrival on loan at the start of September, is two weeks away from recovery after suffering a calf injury.
In the same time Welbeck has started all bar the Capital One Cup defeat at Southampton for Arsenal and scored five goals.
"When you keep Welbeck then you don't give any chance to youngsters and that is also our philosophy," Van Gaal said.
"And then also we could buy Falcao. If that is not enough reason, then I don't know what is - then I'm not a very good manager. I don't have to prove that (decision was right.) Why do I have to prove that?"
The doubts about the transactions are compounded by the struggle Falcao, who joined from Monaco with a view to a permanent move in the summer, has had to make any impression when fit.
His injury problem has been exacerbated by Van Gaal making another tactical switch to 4-2-3-1, to protect a porous defence, leaving only one striker's spot, which Robin van Persie has claimed - despite scoring only three goals himself this season.
Van Gaal retains faith that the wisdom of moving for Falcao will be justified.
"I hope so. I hope so. That is clear I think, but do you think that we expected he would be so many weeks injured?
"Yes we knew he had a cruciate problem last season but because of that maybe we didn't buy him."
Van Gaal admitted that the wisdom of selling Welbeck would only be clear at the end of the season.
"It was a very good decision for him because as a starting player he develops himself much more," he said.
"And if it was the right decision for Manchester United depends on how we play and we score and in what position we shall finish in the league.
"We have a different philosophy to Arsenal. They have a manager who has been there 18 years and the playing style in 18 years the same. So that is very different.
"Here Danny Welbeck doesn't play every match. Mostly he doesn't play."
Wayne Rooney thinks Welbeck did the right thing by leaving Manchester United for Arsenal this summer.
Many United fans were shocked earlier this year when Van Gaal sanctioned Welbeck's £16million transfer to the north London club.
Welbeck is a life-long United fan and joined the club as an eight-year-old having grown up in the Longsight area of Manchester, just four miles away from Old Trafford.
During his 11-year spell at United, Rooney watched the pacy forward progress from teenage prodigy to first-team striker and admits it will be strange to play against the 23-year-old striker tonight.
"Of course, Danny has been here all of his life," said Rooney. "He is a Manchester lad so it is weird seeing him there."
Welbeck scored 29 times in 142 United appearances, but since his move he has found the net on 10 occasions for club and country.
Rooney, who played alongside Welbeck for England against Slovenia and Scotland in the recent international break, thinks leaving United has been beneficial for his former team-mate.
"I think, for Danny, and for his own personal career, it was probably the best move for him," Rooney said.
"He's done great and scored a few goals and is playing well. Danny gives you what he always gives you - a good shift. He works hard for the team. At times, as I said to him, he works a bit too hard but he's scoring goals."
Arsenal nor United are considered a serious title contender this season. For Rooney, the fixture still brings back fond memories, though.
"Beating them in the Champions League semi-final (in 2009) was probably the highlight," he said.
The same fixture last year ended in a dull 0-0 draw, but given the poor defensive record of both teams, it is unlikely the scoreline will be the same this season.
"It's always a tight game and whoever gets the first goal normally wins or gets a result," the 29-year-old said.
"We have to go there with a good team shape and a good unit to make sure we do everything right.
"Arsenal have got a good squad with a lot of young players and a lot of English players which is great for England.
"We know they play with a lot of energy and we'll have to be at our best to beat them."
United have doubts over no fewer than 12 players.
Chris Smalling may be recalled in defence to partner Ulster youngster Paddy McNair, despite a sending-off in the Manchester derby which called his game judgement into question.
Premier League: Emirates Stadium, 5.30pm (Sky Sports 1)