Getafe played very defensively at home today, so of course that has made it difficult for Barcelona to score goals. Lewandowski had several chances, so did Raphinha and several other players, but they were countered by the good performance of Getafe goalkeeper, Soria. I agree that injury problems meant that Xavi had to rely on a few subs to play an active part in the game. Pedri, Dembele and De Jong are still injured and of course that comes at a cost when the rest of the players are not at their best.
Most likely this match doesn't mean a lot to Barcelona, because they seem to be slackening their efforts as they have a comfortable points gap with Real Madrid. On the other hand, Getafe are searching for every point that can get them far from the relegation zone, so they have achieved a convincing result today against the leader of the standings table. However, Barcelona has another competition with Real Madrid on the level of the top scorer, Lewandowski has been the top scorer till now, but Benzema is only 3 goals behind him. That explains why Xavi didn't replace him. Unfortunately, he wasn't able to score in this match.