Chelsea have been warned they could set an unwanted Premier League record of most goals conceded this season.The Blues’ defensive issues were laid bare during Friday’s 3-0 defeat at Brentford.Rory Jennings fears Chelsea will set a new Premier League record for goals conceded this seasonGettyXabi Alonso’s side have now conceded 12 goals in just five league matches so far this season.It took until November for Chelsea to concede as many times last term, with the figure reached in their 13th fixture.Chelsea warningtalkSPORT’s Rory Jennings is now concerned they could make history if they do not improve defensively.He joined Jeff Stelling and Andy Townsend on Tuesday’s Breakfast show to reflect on Chelsea’s performance against Brentford.Jennings admitted: “Chelsea shouldn’t be losing at Brentford. They were worthy winners, they were far better than us, but we were the architects of our own downfall as well.“We were so basic. Every time they broke, Kevin Schade just felt like he was in loads of space.“You look at the way we concede goals from set pieces, that needs to be nullified.”As for the defence, he continued: “They’re on 12 goals conceded. We’re on course for Swindon Town’s record. We genuinely are.“If it continues at this rate, we’re going to concede in excess of 90 goals this season. That needs to stop.“I don’t quite know where it’s going so wrong. Xabi Alonso came in, it was clearly the remit to sort out the back line.Austin MacPhee joined the club as set piece coach this summer but is yet to make a difference, says JenningsGetty“We brought in Austin MacPhee, who was supposed to sort out the set pieces and what you saw at Brentford could easily have been overseen by Liam Rosenior, let alone Xabi Alonso.“The upturn hasn’t really happened, there have been moments, there have been glimpses of the brilliance that we hoped to see, but it’s been a fairly stuttering start to the season which is fairly depressing.”Former Aston Villa set piece coach Austin MacPhee joined the club in July after leaving his role at Villa Park.However, Brentford opened the scoring from a corner on Friday night.Unwanted Premier League historyThe three goals scored by the Bees leaves Chelsea on course to concede 91 league goals this season.If realised, it would see them become only the second club to concede more than 90 times in a 38-game Premier League season.Chelsea have already conceded 12 goals in five Premier League matches this termGettySheffield United currently hold the record with 104 conceded during the 2023/24 campaign.The Blades surpassed the previous figure set by Swindon Town in 1993/94 of 100, although Swindon’s came during a 42-game season.As for Chelsea, they have yet to keep a clean sheet this term and have conceded at least two goals in each of their Premier League outings.The Blues currently sit tenth in the table, already eight points adrift of leaders Manchester City.Alonso now faces a three-week international break to find a solution to their defensive woes.Chelsea return to action at home to Bournemouth on Saturday, October 10.