Alexis Sanchez’s experience and quality will add a new dimension to Manchester United’s attack said manager Jose Mourinho.
The Chile international, 29, set up two goals on his debut for his new team in a 4-0 FA Cup fourth-round win over Yeovil.
“He is a fantastic addition,” Mourinho told BBC Sport.
“His choice for the second goal is a choice that a player like Marcus Rashford is too nervous to make.”
He added: “Alexis brings maturity and class.”
Sanchez signed for United on Monday with Henrikh Mkhitaryan heading in the opposite direction to Arsenal.
With Zlatan Ibrahimovic acting as back-up to £75m summer signing Romelu Lukaku in the central role, Sanchez is expected to compete with the likes of 20-year-old Rashford, Anthony Martial, Jesse Lingard and Juan Mata for a role just behind.