Marcus Rashford thinks Wayne Rooney's England career is "nowhere near over", despite the captain being left out of two straight international squads.
His team-mate Rooney, though, is not part of the set-up after manager Gareth Southgate stressed his rivals for selection in attack are in better form.
The decision cast further doubt over whether Rooney, who also faces an uncertain future at United, has hopes of reviving his international career, one year away from the World Cup in Russia.
But Southgate has stressed he has not written Rooney off and Rashford thinks it would be a huge mistake to give up on the 31-year-old.
"Wayne is a massive influence around the whole squad," Rashford told reporters.
"He still has a lot to do in his career. There's still a lot trophies he will hope to be playing for. Knowing Wayne, it's nowhere near over."
United manager Jose Mourinho got his wish with Rashford's selection to the England senior team, meaning he will not play a full tournament at the Under-21 Euros and get the chance to rest after a gruelling season for his club.
"Southgate had to think about what's best for England and for me as a player," said Rashford, who made 53 United appearances in 2016-17.
"I'm happy to be with the seniors and to continue my development. It's important to be on the same page.
"I didn't actually have a conversation [with Mourinho over the Under-21s]. What he said to the media is what he said to the media but he kind of just left everything and let it play out itself.
"Whatever age group you are called up to, it's important to have the mindset that you're going to achieve great things.
"To me, I have not been fast-tracked, there's been a lot of games. I feel comfortable in the position I'm in.
"England and United have both dealt with it in a positive way and they are dealing with the situation well.
"A lot of it is mentally. If you prepare yourself mentally the right way then physically you will be able to push yourself through it."
England face Scotland in World Cup qualifying on Saturday, with the France friendly at Stade de France next Tuesday.