Brentford won 2-0 at London stadium through goals from Igor Thiago and Mathias Jensen.
Andrews said afterwards: "Very impressive. You feel like from training sessions there's a feel around the group. I felt really good the last couple of days what I've been seeing and feeling from the group.
"That doesn't always materialise when it comes to the games. I thought it did tonight. I thought we were excellent. We approached it in a very positive manner. A lot of courage, a lot of personality.
"I felt pretty comfortable, I'll be honest. It's constant learning from me, certainly. And us as a group, us as a team, how we manage those situations, what the opposition throw at you."
He also said of goalscorer Thiago, "The worst part about being a player is being injured. Thiago came to the country at a similar time I joined Brentford and I felt bad for him. I feel really like he was hurting.
"When he came he got injured so early on he couldn't do what he loves doing, so I always make an effort with injured players because I've been in that situation, I know how it feels.
"I've got a lot of belief in Thiago. I think he's a phenomenal person, the appetite to get better every single day and the positive nature he brings and his demeanor every day. And as everybody's seen now, he's a handful."