Marcus Smith impressed Harlequins director of rugby John Kingston after producing another promising display, even if it was not enough to prevent a 31-28 Aviva Premiership defeat by Leicester.
Smith is viewed as a possible bolter for the 2019 World Cup by Eddie Jones and has been called up for the coming three-day training camp in Oxford ahead of the autumn series against Argentina, Australia and Samoa.
Despite being targeted by Leicester, the 18-year-old fly-half was sharp and brave before leaving the pitch with a tight calf in the 61st minute.
"Marcus was excellent, he did what was asked of him. His development as a player is continuing to go forward," Kingston said. "I understand the attention he's getting because he's started the season strongly and is doing so well."
Kingston highlighted a number of instances in which Leicester were able to escape a yellow card in a chaotic clash at Twickenham Stoop that was settled by two late penalties from George Ford.
Dan Cole could have been sin-binned for a deliberate knock-on, Telusa Veainu appeared to elbow Marland Yarde and Ellis Genge clearly caught the ball in an offside position.
"That [the Veainu challenge on Yarde] was a massive, massive decision. Was it a no arms tackle? Look for yourself. But it's gone and it's finished," Kingston said.
"There are such fine margins in these games and most people would have expected the Leicester player to get a yellow card for a deliberate knock-on.
"But I'm sure Leicester will look at a couple of things and feel they should have had something.
"It was a roller-coaster with two very good sides going at it hammer and tongs. A couple of things went for Leicester, the turning points.
"I can't question the attitude and commitment of the players, they worked their backsides off. We have to take the hurt from losing very, very badly."
Leicester boss Matt O'Connor welcomed a second successive Tigers victory.
"Never in doubt? It was always in doubt! It was a tough game of footy and both teams had really good intentions about playing ball in hand. It delivered as a spectacle," O'Connor said.