After just two minutes, it looked like Chelsea were on their way to a comfortable victory. Timo Werner had opened the scoring against Zenit St. Petersburg, following a bright start by the Blues.However, the UEFA Champions League is always full of surprises. Just like Chelsea surprised everyone to win the tournament last season, they were on the receiving end of a shocker this time.The Blues fell 2-1 behind in the first half, after goals from Claudinho and Sardar Azmoun turned the game on its head. However, Chelsea returned strongly for the second half, and led 3-2 after Romelu Lukaku and Werner found the back of the net. The Blues, though, failed to hold on to their lead as a late collapse allowed Zenit to snatch an equaliser at the death.Chelsea FC@ChelseaFCSpoils shared tonight. ⏱#ZenChe | #UCL7:38 AM · Dec 8, 2021127811632Spoils shared tonight. ⏱#ZenChe | #UCL https://t.co/aIEP6tiMohBlues blow chance to top groupManager Thomas Tuchel was forced to name a much-changed line-up due to a growing list of injuries the team has had to contend with in recent weeks.With Jorginho, N’Golo Kante and Mateo Kovacic all ruled out, the German manager opted for a makeshift midfielder partnership of Ross Barkley and Reece James. The out-of-form Saul Niguez was also shifted to the left wing-back position.Chelsea, though, struggled for much of the game, and were surprisingly disorganised at the back. All the goals scored by Zenit were poorly defended by Tuchel’s men.This was clearly a depleted Chelsea team, and it seems the injuries are beginning to affect their momentum. A win would’ve guaranteed them top spot in their group, but a draw now leaves Chelsea in second place behind Juventus.Squawka News@SquawkaNews2021/22 Champions League Group H final standings:◉ Juventus (15 points)◉ Chelsea (13 points)◎ Zenit (5 points)○ Malmö (1 point)#UCL7:41 AM · Dec 8, 2021280342021/22 Champions League Group H final standings:◉ Juventus (15 points)◉ Chelsea (13 points)◎ Zenit (5 points)○ Malmö (1 point)#UCL https://t.co/nd5vKJuxM8Chelsea facing difficult route in knockoutChelsea missed the chance to finish as group winners. Now they risk drawing a very difficult opponent in the last 16 of the Champions League.As things stand, The Blues could face either Real Madrid, Ajax or Bayern Munich in the next round, a situation they could have avoided by beating Zenit."We were forgetting why we were the better team, which was because the level of concentration and the level of physical investment was high enough to be the better team," Tuchel lamented, as quoted by ESPN.The Chelsea manager rued his team’s loss of intensity and concentration, saying in this regard:"Once this drops even 10%, once we start managing results and change our behaviour because of what the score is, we get punished. That happened to us at West Ham, and it happened to us today.""It's very easy - you have to have a higher level of sprints, a higher level of intensity, a higher concentration level. The basics need to be pushed to a higher level. The quality is high, the technical level is incredibly high, so you need to do your stuff on the highest level. If you don't do it, you get punished, and this is what happened."Chelsea haven’t been at their best in recent weeks, winning only one of their last four games. Talks of a crisis may be premature, but they have to improve quickly to remain competitive on all fronts.