It was an emotional night for Bellerin as he returned to the first team after more than nine months out injured.
"I think Hector's attitude is a very big attitude to help us," Emery said. "When he was injured he was still a big mentality in the dressing room helping us.
"He assisted for [Joe] Willock to score and also to have different options in the squad and first XI is good. We are going to play a lot of matches and tonight was his first 15 minutes [with us], which is really important.
"He wanted to play 90 and yesterday he told me he's ready and wanted to play, but we decided to give him less minutes than 90. He played with the under-23s on Friday and also they are the first matches for him. We need to do it progressively and the doctor said to us that we are going to do it like that.
"I think no [he can't play 90 minutes against Manchester United next]. Maybe in his mind yes, but we need to listen to the doctor and the doctor wants to do it progressively. Really tonight is the first day and the first minutes, and we are going to maybe share some minutes with the under-23s.
"It depends how he's feeling, but in his mind he's feeling very well and I think the first minutes tonight were amazing for him. We are going to use him with Ainsley [Maitland-Niles] and Calum Chambers to help us in this position. The most important things about Hector are his attitude and experience. He's wishing to help us."