Arsenal boss Unai Emery said he has "confidence" Shkodran Mustafi can perform for the club if called upon this season despite telling him he can leave the Emirates Stadium this summer.
The Gunners brought in David Luiz before the Premier League summer transfer deadline on Thursday, but they can still sell players abroad until September 2.
Per Goal's Charles Watts, Emery revealed he had discussed a potential departure with Mustafi: "I spoke with him when we finished last season. I spoke with him when we started pre-season and I spoke with him also two weeks ago saying maybe there was the possibility he can leave."
He added: "At the moment he [Mustafi] is here and really if we need, he plays with us. I have confidence he will do well."
With Luiz added to the squad as a replacement for Laurent Koscielny, the Gunners have six senior centre-backs.
Alongside Mustafi and Luiz, they also have Sokratis Papastathopoulos, Konstantinos Mavropanos, Rob Holding and Calum Chambers.
The German joined Arsenal in 2016, but his time at the club has been characterised by lapses in concentration and defensive errors.
In the Gunners' final game of pre-season, Mustafi came on as a late substitute and failed to track Luis Suarez as the striker netted in the 90th minute to win it 2-1 for Barcelona.
Fox Sports' James Dodd and sports writer Robert Lusetich are hoping the 27-year-old will be moved on this summer:
Mustafi has been booed by some Arsenal fans during pre-season. Should he be called upon in the coming weeks before moving on or if he stays at the club beyond the deadline, Emery wants him to be confident:
"Some supporters can believe in or like one player more than another player, that's normal.
"But inside I want to be strong and to create a big squad with a big, competitive, winning mentality and above all, one with confidence in each other.
"If he [Mustafi] needs to play, he can help us with confidence."
Watts took issue with the treatment the defender received during Arsenal's pre-season tour of the United States:
Charles Watts @charles_watts
Whatever your views on Mustafi, he’s an Arsenal player and unless that changes in the next few weeks then Emery is going to need him, especially after his captain downed tools and threw his toys out of the pram. What good will booing him do? Never understood it, never will.
The jeers will have done little to settle any nerves the player may have, which won't help him cut out the mistakes in his game if he's needed this season.
A departure would be best for all parties and allow Mustafi to restart his career elsewhere, but having spent more than £35 million to recruit him from Valencia, the Gunners need the right offer to come in for him for that to happen.