McEachran, who was playing Champions League football at 17, was touted as the next big thing at Stamford Bridge, where two years ago he was named Young Player of the Year.
But the midfielder's career stalled badly following an unsatisfactory loan spell at Swansea that threw his development off course.
"I was playing at Chelsea when I was 17 and was progressing but then I stalled a little bit," he said.
"But I've gone to Middlesbrough and been playing every game, doing well and now I need to kick on.
"A lot of it (the stalling) was down to opportunity, really.
"There were a lot of things happening at Chelsea with managers and when you are a young player you need to get the trust of the manager for him to play you, so it was hard.
"Playing week in, week out for Boro has really helped me. The Championship is a tough division and it has helped me grow up and become a better player."
McEachran, who played for the England Under-17 team that lifted the European Championship in 2010, also hopes to be included in Stuart Pearce's Under-21 side for this summer's European Championships in Israel.
He said: "I was in the 17s when we won so I've got experience of the finals.
"I am hoping I won't be disappointed again and that we can go on and win this one.
"Winning with the 17s was a great experience because we were the first England team to win a tournament for years.
"All the players who were in that squad will help us this time because we know that feeling of winning.
"Everybody wants to win and I think we have a great chance."