Whe loan to Barcelona, he has showed impressive performance, even then he managed to become Xavi mainstay in every game they played, but unfortunately his poor relationship with Atletico fans and coaches actually made him have to leave for Chelsea as one of the recruitment requirements for Connor Gallagher at that time, at the beginning of the season he was actually able to compete in the Chelsea first squad but slowly he began to be eliminated, especially now that he has an injury that makes it difficult for him to get a place in the Chelsea first squad again later, so indeed moving to another team (Aston Villa) which can guarantee a place in first squad and more playing time is certainly a good option for his career at this time.
Injuries are a big enough problem and it is still quite difficult for him to avoid and staying with Chelsea will make it difficult for him to get a main place in the team.
If Aston Villa are interested in signing him then I am sure that would be a much better place for him to play and not getting enough first team football could make his career even more uncertain.
going off on loan from Chelsea is a bit understandable but it still doesn't look right the way he is getting less amount of playing time at Chelsea even with the quality he possesses. Aston villa is surely not a bad option for him as long as he is going to get more playing time and hopefully become one of the regular starters for Aston villa. himself, pedro nato and nkunku have unfortunate suffered the effect of being in a team that has a large number of squad which has resulted in them being on the bench for most of Chelsea games, which the two of them going out, there performance will determine if they will be recall after the expiration of the loan duration. whatever Chelsea does in this current transfer windows, they should not sell or give out key players that have good goal scoring prowess and think that with just Jackson and palmer they stand the chance of getting back at top four of the table. as much as they are pushing out some of her good players, they also should be ready and willing to bring in good attackers that can complement what Jackson is doing upfront and tat at the same time has the quality of scoring a lot of goals since that is what is missing in the team.