The midfielder's transfer was announced on Thursday amid rival interest from Wigan Athletic.
â€śI didnâ€™t expect it,â€ť Pappa told MLSsoccer.com. â€śI was thinking I was just going to finish the season. I think they pushed a lot, the Fire, to make this happen as soon as possible.
"Now Iâ€™m looking forward. This is a good opportunity for me.â€ť