Athletic Club is a great team and they will want to beat Barcelona at the end of this season. Barcelona have already secured their trophy in La Liga and they will want to continue their winning streak. Accordingly, they may not field a team with second-tier players. I think Barca will play with their full strength and will try to beat Athletic Club. We can say for sure that it will be an exciting match between both the teams and Barca will have a higher chance of winning. Although Barca is ahead in the win statistics of these two teams the win or loss depends on the best performance on the specific day to get the win.
This match is not too important for Barcelona so I think they will not field full strength, maybe Hansi Flick will give a chance to play to player B, something that is usually done by clubs that have clearly achieved their goals on the other hand for Atletico Club this match is quite important to maintain their place from the pursuit of Villarreal, at least Atletico Club only needs to get a draw. A match that I think is not interesting enough to make a bet.