Arsenal boss Unai Emery says Hector Bellerin will not play against Manchester United despite his impressive cameo on his return from injury against Nottingham Forest in the Carabao Cup.
The full-back has been in the treatment room since January after suffering an ACL injury in the 2-0 win over Chelsea.
His arrival on 77 minutes in Tuesday's 5-0 victory at the Emirates - replacing summer signing Kieran Tierney - was met with a huge ovation from the home fans.
He revelled in Arsenal's domination of Forest, grabbing an assist within three minutes of his arrival from the bench.
Emery has a selection headache at right-back for the fixture with United, live on Monday Night Football, with Ainsley Maitland-Niles available after serving a one-match ban, Calum Chambers putting in a solid performance against Forest and Bellerin back in the first-team fold.
However, when asked if Bellerin could feature in Monday night's showpiece encounter, he replied: "I think no. Maybe in his mind yes, but we need to listen to the doctor and the doctor wants to do it progressively. Really tonight is the first day and the first minutes, and we are going to maybe share some minutes with the under-23s.
"It depends how he's feeling, but in his mind he's feeling very well and I think the first minutes tonight were amazing for him. We are going to use him with Ainsley and Calum Chambers to help us in this position. The most important things about Hector are his attitude and experience. He's wishing to help us.
"When he was injured he was still a big mentality in the dressing room helping us."
Analysis: How did Tierney, Holding and Bellerin do?
Along with Bellerin's return, Tierney was handed his Arsenal debut and Rob Holding made his first appearance since December as he returned from injury.
Sky Sports' Simeon Gholam reporting from The Emirates:
Rarely tested in a defensive sense, Tierney instead proved what an impressive attacking talent he was throughout the first half as he regularly beat his man down the left side before putting in brilliant cross after brilliant cross.
Within a minute he had done just that, and continued to do so as he created fine chances for Joe Willock and Emile Smith Rowe before the break.
Holding, meanwhile, also faced little attacking threat from Forest but provided an assured presence at the back throughout, and showed his aerial prowess with a well-taken header from a corner in the second half.
The capping of a fine night for Arsenal was the return of Bellerin, who was introduced as a second-half substitute for Tierney and immediately assisted their third.
There will be far sterner challenges ahead but there is little doubting that Arsenal look a more formidable outfit with these three at the back.