The duo are both out of contract at the end of the current campaign and have shown no signs of agreeing fresh terms at the Emirates Stadium.
Iwobi fears losing both players, admitting that simply being given the chance to train with the talented attackers over the past couple of years has been an "amazing" experience.
"When they are fit they are unstoppable. They are both capable of changing a game or a season," he told The Sun. "They have a big decision to make. But it would be a huge setback to lose them because from the stats you can see we do need them for their goals and assists.
"For a team like Arsenal, we need to be aiming for the top four and we need what they bring. It will be great for them to stay. I've learnt a lot from them. Just the opportunity to even train with them has been amazing. They are two top-class players with great experience having played at the top level."
Nigeria international Iwobi has played 65 times for Arsenal since breaking into the first-team ranks in 2015.