but you should invest more time in why we did not create chances ...
there was no scene where sali got the ball and giovinco at this position would have scored a goal or would have easily assisted ... there was just one cross by sali that went over the goal and if gio would have been there, yes there might have been a better pass ... wow ... a small chance for one assist for many occasions where salihamdzic did help a grygera who would have had to play against two or more zenit players on his side if not for sali...
as you saw, we CAN defend against Zenit at home ... if you did not already got it ...
it worked and we got 3 points.
furthermore reading in the book of tactics there is a small chapter about "subtituting a player that was just brought on before" ... it reads "you don't do that". there are very few situations a coach would consider to take off a player he brought in as substitute ... (only situations i remember is, when a goalkeeper gets red and the backup keeper has to come in)
Grygera had a nice game but is in no way able to stop the opponent when more than one opposing player come over his side ...
My recommendation for you
"Amazon: Football Tactics"