They are currently facing a spell that sees them play 13 games in six weeks.
And teams are trying even harder to stop a team that managed 100 points last term.
"It will be a very tough year, we knew that," Silva said after his side's 2-1 win at Watford.
"All our rivals are doing better this season than last season. So we have to focus on ourselves and then we'll see how our opponents do.
"Last season we had two more points -- this season we already conceded two draws and last season we only had one at this point of the season. I don't know if we're doing better but I think we're doing well.
"We just want to keep doing the same thing: forget about last season, know what we did last season was amazing breaking all the records.
"But this is another season and we have to try to win the Premier League again, against different opponents, stronger opponents in my opinion and it will be a tough season for us."