It came as stand-in Knights captain Dane Gagai lamented a crucial refereeing call that helped the visitors seal their James Tedesco-inspired victory.
Hard-nosed forward Radley suffered his second game-ending head knock of the season attempting to tackle Fletcher Hunt in Saturday night's win in Newcastle.
Radley has one of the most extensive concussion histories in the NRL, estimated to have gone down with seven game-ending head knocks in the past four seasons.
He will miss at least next week's clash against North Queensland before the Roosters have their third bye of the season.
Robinson was in charge when concussion forced the retirement of Roosters legends Jake Friend and Boyd Cordner and appeared level-headed addressing game-ending head knocks to Radley and Egan Butcher on Saturday.
"They said they were close to passing (head injury assessments)," Robinson said.
"They're going to have this week and then our bye week so they're going to have some rest on the back of that.
"Do the right recovery, he gets the bonus of an extra week (off)."
Errors meant the Roosters struggled for any kind of ascendancy in the first half and trailed 6-0 when Jack Cogger put Kyle McCarthy over on the back of a Dylan Lucas break.
But Tedesco stepped up in the second half and proved the difference in a contest missing a combined total of 17 players to injury, suspension and State of Origin duties.
At the halfway line, Tedesco broke through Kai Pearce-Paul and Jackson Hastings - playing his first game of the year - and reached around to find Salesi Foketi.
The up-and-coming forward grabbed Tedesco's one-handed offload and tore past Hunt and through James Schiller's tackle to score his first NRL try.
The four-pointer came the set after right winger Schiller went within inches of giving the Knights a three-score lead, only to drop the ball over the try-line.
A profane chant rang out from the Knights' home crowd after the Roosters' ultimately game-winning try, again set up by Tedesco.
The fullback put a grubber kick through the line and Siua Wong was ruled to have grounded the ball with his forearm.
Knights coach Adam O'Brien would not be drawn to comment on the call.
"I'm going to show real self control this week," said O'Brien, who received backlash for criticising Newcastle's fans for booing in round 14.
Gagai said the call was "a tough one to swallow".
"They said there was no separation but I've never seen someone control the ball with their forearm before," Gagai said.
"But in saying that, we had our opportunities to win the game."
Dom Young was seen embracing Roosters teammates at fulltime, with a mid-season return to the Knights set to be finalised imminently.
"It's pretty clear that he's going to be up here (in Newcastle) from Monday," Robinson said.
Hastings was solid without having any moments of brilliance in his first game for the injury-stricken Knights since July last year.
The out-of-favour playmaker looked particularly dangerous linking with Pearce-Paul on the right side.
But Hastings was caught with the ball on the fifth tackle inside the red zone in the second half, one of many times the hosts failed to capitalise on ample chances.
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