The England international has embraced the addition of another left-back as the Red Devils bid to bounce back from a dismal start to the season
United paid €17 million (£15m/$20m) to lure Telles away from Estadio Do Dragao on deadline day, with the 27-year-old signing a four-year contract.
Telles will now be expected to compete with Shaw and Brandon Williams for a regular spot in Ole Gunnar Solskjaer’s starting XI.
Shaw has come under scrutiny at the start of the 2020-21 campaign, with United shipping a total of 11 goals in their opening three Premier League fixtures.
Telles is being tipped to go straight into Solskjaer’s line-up when his side returns to top-flight action against Newcastle on Saturday, having benefitted from two weeks to reflect on a 6-1 defeat to Tottenham before the international break.
Edinson Cavani and Facundo Pellistri joined the Portuguese in Manchester on deadline day, increasing United’s overall tally of summer signings to four, with Donny van de Beek brought in from Ajax for £35m ($46m) back in September.
Shaw is more concerned with the overall benefit the club’s recruitment drive could have on the squad rather than his own position in it, with everyone pulling in the same direction ahead of a crucial trip to St James’ Park this weekend.
“Competition for any team is a must,” he told the Red Devils’ official website. “There is competition for every single spot and you’ve got to be ready for it, work hard and give the manager a decision harder than what he’s had to make before.
“Like I said, competition is very healthy for the squad, it’ll push everyone even more because everyone wants to play.
“It [Saturday’s match] is one we all want to play in. We all hoped it would be a bit earlier, to be honest, as the last game wasn’t good. We’ve had a lot of time to think and work and be ready for this.
“We need to win it. It’s a must-win game and we want to put things right. We’ve got very important games coming up. Everyone is looking forward to working hard so we’re going to be ready for it.”
Asked what United will need to do to bounce back from their heavy loss to Spurs against Newcastle, Shaw responded: “We need to control the game.
“We need to create chances. We need to be clinical and, especially at the back, we need to be more solid.
“Not just as a backline but throughout the whole team, a bit more defensively solid and a bit more compact. I think you’ve probably seen in the last few games, we were easy to play through.
“Look, we can count it as down to mistakes and people can put their hands up. Maybe I’ve made a couple of mistakes and so have others in the games.
“We’ll put our hands up and move on from that but I think everyone needs to give a little bit extra, including myself. We want to and need to. This club deserves that.”