The 19-year-old had plenty of attractive alternatives, but not for the first time this summer, manager Tony Mowbray beat off the competition, convincing him to come to the Riverside.
"The competition was quite stiff, not just from the Championship but Premier League clubs also wanted to take him on board," said Mowbray.
"The boy felt he needed to come and play some football and we'll give him the platform to do that if his performance levels warrant it.
"I've spoken to a few of the Chelsea staff and they appreciate the way we like to play and the reputation we have, and I think that helped our cause.
"He went on loan to Swansea last season and didn't play, for whatever reason. Hopefully we can find the right environment for him to come here and impact on our team and help us."
McEachran trained with his new team-mates on Monday after a agreeing a one-year loan deal and goes straight into the squad for the first home game of the season, against Burnley.
But while Mowbray is delighted with is new recruit, he says it's important to keep it in perspective and he won't be piling too much pressure on the England U-21 international.
"He's only a very young by who has bags and bags of talent and he has to apply that talent on the Championship stage," he said.
"It's different to the Premier League, it's more hurly-burly. Whether he can cope with that physically is a challenge for him, of course, but with the ball he will make some good decisions and there will be some passes that can make an impact for our team.
"He's in the squad, he's fit, he's been on a pre-season tour with Chelsea and played three or four games over in America.
"I see no reason why he can't come straight in and we'll see if he makes an impact."
McEachran was recently handed a five-year contract by the Blues, who clearly rate him as one of the future.
"Chelsea see it as a development for the boy," said Mowbray. "I've always liked his talent. He'll bring ball-retention, he's a very technical and creative footballer.
"He's a young guy I think has an interesting future in the English game and I can see him being a top, top player in a few years' time.
"Hopefully his ability will rub off on our team. Josh can pick and see passes and he's not in the Mustpaha Carayol mode, who's fast and dynamic and can go past players, he's a player with a lovely appreciation of the football. But I'm sure he will help our cause."
Meanwhile, Mowbray is working hard to make a further breakthrough in the transfer market before the August 31 deadline.
"We probably do need at least another one in," he said.