England manager Gareth Southgate admits only time will tell regarding how Cristiano Ronaldo's return to Manchester United will impact Marcus Rashford and Mason Greenwood.
Rashford is currently out after undergoing shoulder surgery last month, while Greenwood has played almost every minute of United's Premier League campaign so far, scoring in each of their opening three games.
Greenwood started the matches against Leeds and Wolves as United's centre-forward, but the presence of Ronaldo has put the spotlight on how Ole Gunnar Solskjaer will line up his team now the Portugal captain is part of his plans.
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Asked if he was concerned whether Ronaldo's arrival would restrict game-time for Greenwood and Rashford or boost the England duo's development, Southgate said: "I think the league is full of outstanding players, so the players are used to that level of competition every week which is fantastic for them.
"We'll just have to see what happens at Manchester United, that's for Ole to decide and manage his squad.
"At every club, we always have to pick up from those selections and how that affects fitness and form.
"It's not an unusual situation for us. We'll just have to see how that all plays out really."
Greenwood has not played for England since making his debut against Iceland last year, with injury ruling him out of Euro 2020 contention, and Southgate had admitted the United forward was in his thoughts despite missing out to Patrick Bamford in the current squad.
Meanwhile, Rashford's last match at any level was the Euro 2020 final - he then underwent shoulder surgery in August, ruling him out for at least two months.
England wary of Poland, Lewandowski threat
England travel to Warsaw to play Poland for their third World Cup Qualifier of September on Wednesday, and Southgate has warned his side not to get complacent after a 100 per cent start after five games.
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"As a team, we have to recognise we are in a good moment and the team is playing well," Southgate said.
"We have a squad of players, any of whom are more than comfortable to play and are playing well.
"But also those moments are dangerous because, if we get any sense of complacency, we are going into a game that will be a challenge.
"It is a high level of motivation but also guarding against a feeling we are better than we are. We are getting a good set of results because we are working hard for each other."
England players were subjected to racism during their last away qualifier in Budapest on Thursday.
While Southgate would not be drawn on the prospects of facing a similar scenario in Warsaw, he knows keeping possession is key to quietening the home crowd.
Southgate added: "We have to approach the game as we did the other night. We know keeping possession of the ball can be a big factor in managing those situations.
"But the flow of the game will be different and we are playing a level of opponent who I think is in a better moment.
"They have won their last two games and have better footballers in the team who will keep the ball a little bit better than Hungary were able to against us."
When England beat Poland 2-1 at Wembley in March, the visitors were without record goalscorer Robert Lewandowski.
He is back to lead the line on Wednesday and Three Lions goalkeeper Jordan Pickford is excited about the challenge of facing the Bayern Munich striker.
"I have just worked hard all week," the Everton player said.
"I have done my stuff with the other keepers and will just be 100 per cent on the training pitch leading up to match-day.
"We know they are a top side and he is a top striker, so we will focus on certain areas and be ready for anything."
Staging the World Cup every two years will be a "strange concept" for a whole generation of football fans, Southgate has told Arsene Wenger.
Southgate revealed after England's 4-0 World Cup qualifying win over Andorra on Sunday evening that he had spoken to Wenger about the proposals and that he is open to the possibility - so long as the football calendar does not become overwhelmed.
"I actually met with Arsene a couple of weeks ago, he was meeting a few different coaches so I have a pretty good idea of the proposals," Southgate said.
"I think the whole calendar needs reviewing. My feedback would be - I don't know - that our generation are going to find a World Cup every two years a strange concept.
"But I also know that things like The Hundred in cricket have been an incredible success, so I'm open-minded about some of those things. But the calendar generally needs to be tidied up. We can't keep adding more things in.
"I agree generally with the concept of better quality matches. Fewer matches, better quality across the board, but there's lots of other things that need consideration and we can't just add more in at the moment."