It's not just "his box" though is it. Our owners want European Success.
At the expense of risking CL qualification, which would be essential for player recruitment, further progress in Europe, as well as growth of revenue and fanbase? Is it really prudent of the club to put their sole focus in the CL, where our chance of winning is rather slim, even if we can get to the final? If we had won yesterday, we would only need 2 points in the next 2 matches for qualification. Now winning against Arsenal (which is not a guarantee) becomes much more important.
On paper yesterday's team should be able to win or draw. Midfield seemed rather solid with Delph and Dinho despite the formation. It didn't work in reality. Some shifted their focus to Wednesday, some were in a rather poor form, and some looked like they didn't want to be on the pitch. Those who are unmotivated, e.g. Kolarov (utterly unprofessional performance), must take the major blame, but Pellers was at fault too. I think he knew that there was a decent chance we would lose with yesterday's personnel. It is obvious why the two full backs were second-choice. And Delph, in his desperation to impress and earn a place on Wednesday, forgot he should not try fancy stuff if he couldn't manage the basics. Sterling was either short of confidence or fitness, or both. He obviously knew that, or else he wouldn't play Kelechi last Tuesday in place of those two. And he did admit he was taking a risk in the post-match conference.
So I think that although Pellegrini wanted to win the game, he would't mind if we lost either. He took the gamble and pinned his hopes in winning against Arsenal, though I don't know where his confidence came from.
I understand the need to rest some players, e.g. Kun, but the full-backs? Would the result have been different if we had played Clichy instead of Kolarov, who was at fault for what, two or three of the goals? The possibilities continue to haunt me and I had to vent my frustratoin a bit. So much for happy revision in knowing that we would be able to finish top 3.