English born Ghanaian Callum Hudson-Odoi has expressed delight in making full recovery from a lengthy injury that nearly marred his career development.The Chelsea forward is back at his best since the arrival of Thomas Tuchel and looks forward to the UEFA Champions League Knockout stages.That injury was definitely a nasty one for me as it took me a very, very long time to recover. It was one of those injuries where it takes maybe years to recover from because its just a big injury, he told Chelseas official website.You lose a lot of muscle in your calf, you definitely lose a bit of speed and stuff like that, so Ive been working a lot with the team and my family members at home trying to get back to how I am right now being fit and being able to sprint how I normally sprint, with the muscle back into my calf, which is a big thing.Ive been working really hard off the pitch to try and get all my muscle and strength back and to get everything to how it was before I got my injury. Everyone has done superbly trying to get me back as quick as possible and I feel like Im back to where I was.Id never had a proper injury like that or never even had surgery prior to that so it was something that was new to me and definitely a big challenge. It was a big setback knowing that everything was going so well, with the Europa League semi-finals coming up and stuff, so it was hard but I tell myself that everything happens for a reason.Chelsea travel to Spain to play Atletico Madrid in the round of 16 on Tuesday, and the forward is positive of a good run in the competition.God justifies everything that you do so Im happy with where I am now and hopefully I keep growing and keep progressing, said Odoi.Im really excited! [for the Champions League] Its a massive game against Atletico, who we know are a big team and are doing really well this season. We want to go into that game with the mentality of trying to win and trying to get through to the next round.It will be a different game to what we were expecting, going to Romania instead of Spain, but its going to be big for us either way.We all know football is a crazy sport and it can go either way. You can be winning one minute and the next minute youre losing, especially in the Champions League.Our aim is just to give it everything weve got and lets see if we can make it through.