Teemu Pukki has also given serious cause for concern, but the manager is starting to see some return from the Finn, who is reported to be interesting Freiburg in Germany.
Overall, though, the attacking trio signed last summer have failed to fire.
Pukki did score his seventh goal of the season at Perth in midweek.
But, like the injury-plagued Boerrigter - who was hooked at half-time - and the misfiring Balde, he has yet to convince he can grab a regular place in Lennon's side.
Leigh Griffiths has shown it is possible to force your way into the starting XI since his arrival in January.
And Lennon has made it clear he is in the market to add even more firepower when the window re-opens in three weeks.
The Hoops boss stopped short of saying the trio are heading for the exit, or on their final chance.
But Lennon left them in no doubt what they have delivered so far has not been good enough.
Asked to sum up their debut seasons, Lennon was succinct.
"Disappointing", was the one-word answer before he added: "I think Teemu has got better as the season has gone on.
"But, Amido would probably say he has not had enough game time, and Derk has been littered with injuries.
"They will maybe think they haven't had the opportunity, but they must do better.
"Pukki, I was really pleased with on Wednesday, so we think he has still got something to give.
"But the other two need to improve dramatically if they are going to make any sort of headway in the first team next season."
Balde was the subject of enquiries from other clubs in January, which were rejected by the Hoops.
Lennon may now consider allowing him to go on loan to get the game time he needs to develop.
He said: "Whether he wants to go somewhere and play consistent football, I don't know.
"We'll sit down and talk about it, maybe in pre-season. But, for the time being, they are still part of what we are doing for next year."
Lennon is not looking to push anyone out the door, even though he plans to recruit more players.
He accepts that, when players come from abroad, they may need longer to settle.
But, the clock appears to be ticking, for Boerrigter especially.
"He didn't cost the money that has been quoted," insisted Lennon.
"He cost around £1million. I've seen quotes of £3m, and that's just ludicrous.
"He gets in for a week and then is out. He's even had a couple of injuries in training.
"I think he will be more frustrated than anyone else with the way the season has gone."