As recently as last month, the 34-year-old made the decision to hang up his gloves after a career largely spent playing in the Premier League and Serie A.
Szczesny's last appearances had come at Euro 2024, making his final outings of an 84-cap international career with Poland.
However, the veteran stopper is now back in the limelight having agreed to come out of retirement to replace the injured Marc-Andre ter Stegen.
The long-time number one suffered a serious knee injury against Villarreal on September 22 and has subsequently been ruled out for the rest of the season.
With spaces still available in their first-team squad, Barcelona have been able to act by signing Szczesny on a contract until June 2025.
Szczesny to challenge Pena
Szczesny was present at Barcelona's Champions League fixture against Young Boys on Tuesday night, Hansi Flick's side prevailing by a 5-0 scoreline.
Inaki Pena made his third successive start for Barcelona in that game, the likelihood being that he will remain between the sticks for the trip to Alaves at the weekend.
Nevertheless, Szczesny will naturally be hoping to make his debut for the La Liga leaders when they play host to Sevilla on October 20 after the international break.
Szczesny's career to date
There was genuine surprise when Szczesny announced his retirement from football, despite there being anticipation over him ending his time on the international stage.
As many as 35 outings were made for Juventus last season, including 27 in Serie A to highlight that he was still performing at a high level.
In total, 404 appearances have been made in the Premier League and Serie A since the 2010-11 campaign, Szczesny representing Arsenal, Roma and Juventus.
With a contract lasting less than a year, it remains to be seen whether Szczesny will be prepared to prolong his career past this campaign.