The Englishman has hit out at Ajax's summer transfer strategy after the club dropped more points.
After a draw against Go Ahead Eagles, Henderson felt the club did not invest enough in the first team.
“They are two great players. Every team would have missed them, of course. But we still have other players, who are also good. Players who can create chances and are especially dangerous in the final third," he said of losing Carlos Forbs to Premier League side Wolves and Steve Bergwijn to Al-Ittihad.
"We managed to do that against Fortuna, but not tonight. Hopefully we learn from it. It’s also not ideal to lose one or two of your wingers on the final day of the transfer market. We have lost quality.
“But with the guys who played today, it was possible. We have to help them get into one-on-one situations, but they didn’t bring anything. It’s not just the wingers, but it has to be better.”