Barcelona will reportedly need to omit Wojciech Szczesny to accomodate goalkeeper Marc-Andre ter Stegen back in their UEFA Champions League squad. The German has been out with a knee injury since September.
In his absence, the Blaugrana roped in former Arsenal custodian Szczesny, who came out of retirement to join the club in October. Impressively, in 19 games across competitions he has played in, Barca have gone unbeaten, winning 16.
The run includes nine straight wins in La Liga, where Hansi Flick's side are three points clear of second-placed holders Real Madrid. However, with Szczesny returning to light training this week, meaning the Pole might be back in action before the end of the season.
That won't be a problem in La Liga, but for Ter Stegen to play in the UEFA Champions League - where Barca have reached the quarter-finals - Szczesny must be dropped from the squad to bring in the German, as per UEFA rules (per ESPN). The rules say:
"Once the injured or ill goalkeeper is fit to be fielded again, he can resume his position in place of his substitute. The return of the original goalkeeper must be announced to the UEFA administration 24 hours before the next match in which the original goalkeeper is due to play."
About the German's possible involvement with the first team in the competition, boss Hansi Flick said:
"We will see, step by step. We have to wait and see what happens. It's no time to make a decision or say anything about that. The good news is that he's in a good moment. Everything is going in the right direction. and we are very happy he's in this stage. We will see what happens."
Barcelona play Borussia Dortmund in the first leg of the last-eight at home on April 9, with the return in Dortmund six days later.
A look at Marc-Andre ter Stegen's numbers with Barcelona

Marc-Andre ter Stegen has been a key player for Barcelona since arriving at the Camp Nou from Borussia Monchengladbach in the summer of 2014. In 420 appearances across competitions, he has kept 175 clean sheets.
He has won trophies galore at the club, including five La Liga and one UEFA Champions League title (as part of a continental treble in 2014-15), among other domestic and continental honours.
This season, Marc-Andre ter Stegen played just seven games across competitions - keeping one clean sheet - before suffering a potentially season-ending injury. Having returned to training, he might still feature for the first team this campaign.