Arsenal, who won their last league title in 2004, made a strong start to the season and were top of the division at the end of December, but lost out to champions Leicester City and are currently third in the table behind Tottenham Hotspur going into the last match of the campaign.
“It was a very strange season in a way,” Cech, who signed from Chelsea in the close season, told the club website.
“If you look at the number of injuries we had, it is not a big number compared to previous years or compared to other clubs. It's not a big difference but unfortunately for us, every time we've had an injury, it's been long-term.”
Midfielders Jack Wilshere, Santi Cazorla and Alex Oxlade-Chamberlain have all had long spells on the sidelines, while striker Danny Welbeck, who made his first appearance of the season in February, faces nine months out after suffering a second serious knee injury against Manchester City on Sunday.
“Unfortunately Jack got injured right before the start of the campaign, Danny had the same problem, Tomas (Rosicky) had the same problem, and these were all long-term injuries. Santi and Alex Oxlade-Chamberlain became long-term injuries too,” Cech added.
“I thought we did so well most of the time to be able to cope with that, but unfortunately in the end we lacked a bit of energy in February and March when we dropped points. This is where the difference was made.”
Arsenal, who end their campaign at home to relegated Aston Villa on Sunday, can finish above north London rivals Spurs if they win and Mauricio Pochettino's men lose their last game against Newcastle United, who are also relegated.
Original source: Injuries, fatigue cost Arsenal EPL title - Cech