The Switzerland international is facing an uncertain future at the north London club following his fallout in spectacular style last month.
Xhaka has often been subjected to criticism from the Gunners supporters for his erratic performances under Arsene Wenger and his successor Unai Emery.
However, the Swiss midfielder was appointed as Arsenal’s new club captain at the start of the Premier League season.
Xhaka had a sensational fall-out with the Arsenal supporters during his substitution in the 2-2 draw with Crystal Palace last month.
Arsenal boss Emery opted to strip Xhaka of the captaincy and appoint Pierre-Emerick Aubameyang as his new skipper.
Xhaka hasn’t featured for the north London side since the incident amid speculation surrounding his long-term future.
But Vieira, who is one of Arsenal’s greatest-ever captains alongside the likes of Tony Adams, admitted that he felt sorry for Xhaka.
“I feel sorry for him because he [was] the captain and he’s going through a really difficult period and really difficult time at Arsenal,” Vieira is quoted as saying by Metro.
“I think we have to remind ourselves that he’s achieved a lot since he’s at Arsenal and he deserves a lot of respect. ‘When you’re a player and don’t perform the way you expect, you get frustrated about yourself.
“And sometimes you say things or do things you regret. I find it really difficult a lot of ex-footballers have jumped on him and being really negative towards him, it’s too too easy.
“I know how good he is and he will come through this difficult period because he’s a strong man, he’s a good player. And he will show how good he is.”
Xhaka moved to Arsenal in a big-money deal from Bundesliga side Borussia Monchengladbach in the 2015 summer transfer window.
The Swiss midfielder has scored 11 times in 143 games in all competitions since his move to Arsenal from the Bundesliga outfit.
Arsenal are in sixth place in the Premier League table and eight points adrift of Manchester City, who occupy the final Champions League qualification spot.
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