Maurizio Sarri was unimpressed with Chelsea's ponderous performance against BATE despite a 1-0 win securing his team's passage to the Europa League knockout rounds.
Olivier Giroud's first goal in 794 minutes of club football was one of few positives from a lethargic display that could well have cost the Premier League side.
BATE were denied by the woodwork three times, including once in stoppage time as the hosts went within inches of rescuing a result in frosty conditions.
Chelsea ultimately clung on to move within a point of confirming their status as Group L winners, although their coach was left concerned.
"We didn't play very well. I didn't like the first half because we moved the ball only slowly," Sarri told reporters.
"It was very difficult to be dangerous, but we were better in the first 25 minutes of the second half. We didn't manage the last 15 minutes well.
"The best thing is the result. It wasn't very easy to play a good game here, with the conditions."
Giroud's well-judged header from Emerson Palmieri's cross in the 52nd minute did provide Sarri with the rarity of two strikers in scoring form following Alvaro Morata's brace in the weekend win over Crystal Palace.
The goal opened Giroud's account under the Italian and was his first for Chelsea since May.
"I am pleased for him. He is very important for us," the Blues boss said.
"I know very well a striker wants to score. For his confidence it is very important."
France striker Giroud insisted he lost no belief in his ability during the drought.
"I maybe lacked a bit of efficiency and a bit of luck sometimes, but you always need to keep working hard in training and keep the faith," the 32-year-old told BT Sport. "That's what I did tonight."
|Impressive Anderson thrashes Nishikori|
|Ozil´s Germany absence a ´pity´, says Sane|
|Rooney: I´ll finish my career in the US|
|McIlroy unsure of 2019 European Tour membership|
|Australian Open dismisses concerns of Federer scheduling bias|
|Hue Jackson joins Bengals staff as ´special assistant´|
|Real Madrid confirm Reguilon injury|
|Higuain handed two-match ban for Juve meltdown|
|Kruis ruled out for England as Jones calls up uncapped quartet|
|A year on from Italy failure, Ventura leaves Chievo after four games|
|Bairstow misses out as unchanged England promote Stokes|
|Recalled Alba denies Luis Enrique bust-up|
|´Unhappy´ Christensen won´t push for Chelsea exit|
|Nadal to make Abu Dhabi comeback in December|
|Taijul helps Bangladesh tighten their grip despite Taylor ton|
|Neymar joining Real Madrid wouldn´t hurt Iniesta|
|It´s just team spirit - Livingston not worried by Durant-Green exchange|
|Trippier out of England squad with groin injury|
|Ex-Sri Lanka international Lokuhettige charged by ICC|
|Former England and Chelsea star Joe Cole retires|
|Nets offer support to LeVert following serious leg injury|
|Panenka proud Sergio Ramos imitates his penalties|
|Liverpool´s Alisson seeks patience to reach potential|
|Anthony Davis leads Pelicans, Clippers hold off Warriors in OT|
|Lindelof rues international break for Man Utd|
|Shaqiri confident in more goals for Liverpool|
|Giants too good for 49ers in crunch time|
|Southgate named honorary Yorkshireman|
|Nicky Butt: Manchester United are low on confidence|
|Criticism of Barcelona star Dembele is overblown - agent|
|Thibodeau discusses Butler trade: We thought this was the best deal for us|
|Acuna, Ohtani win rookie of the year awards|
|LeBron James on Lakers’ early season struggles: ‘I almost cracked’|
|Welbeck has successful second operation on broken ankle|
|UEFA warns FFP cases can be reopened based on ´new information´|
|Foakes to keep England place for second Test|
|WATCH: Rooney looking sharp in England training return|
|Mbappe: Money in football is truly indecent|
|Djokovic back to brilliant best as Isner is beaten|
|Celta Vigo replace Mohamed with Cardoso after Real Madrid defeat|
|Joshua intrigued by Usyk, says Hearn|
|Ibrahimovic beats Rooney to MLS Newcomer award|
|Rams WR Kupp out for season with torn ACL|
|Sturridge denies ever gambling on football following FA charge|
|Koeman understands De Ligt´s Eredivisie frustrations|
|Jimmy Butler trade: 76ers acquire Timberwolves star in blockbuster deal|
|´Improve your attitude´ - Deschamps issues Dembele warning|
|Sturridge charged with misconduct over alleged breach of betting rules|
|Saints sign Marshall following Bryant injury|
|Mendy suffers knee injury, leaves France squad with Lacazette|
|Zverev beats Cilic in error-strewn London battle|
|Rafinha replaces injured Casemiro in Brazil squad|
|´One-dimensional´ Australia batsmen need work before World Cup - Finch|
|Mancini keen to work with ´incredibly gifted´ Tonali|
|Italian manager of the year Allegri targets long Juve stay|
|Injured Lee departs as Wales prepare squad for Tonga|
|Conte content to wait until June for coaching return|
|Etzebeth set to return, Whiteley a doubt for Scotland Test|
|In-form Verstappen does not need distractions from 2019 challenge|
|FA asks Guardiola to explain Manchester derby referee comments|
|LaLiga MVP Messi hopes the division stays wide open|
|Murray and Henshaw out of All Blacks Test|
|Injured Man Utd duo Pogba and Martial drop out of France squad|
|Modric cannot always be the best - Dalic|
|Very troubling times - LeBron James alarmed by gun violence|
|Bayern confirm Ribery ´altercation´ with reporter|
|Madrid hit by injuries to Nacho and Casemiro|
|Record-breaking Mushfiqur torments Zimbabwe|
|Spartak Moscow appoint Oleg Kononov|
|Rooney predicts ´exciting time´ after being named in MLS Best XI|