Dan Biggar's first game for Northampton Saints since being announced in the British and Irish Lions touring squad last just 20 minutes.
The Welsh flyhalf threw himself into harm's way but came off second best as he failed an HIA and did not return to the pitch.
A nasty head clash with Billy Twelvetrees as the pair both scrambled to collect a loose ball. Biggar was down for several minutes as medics assessed him before he left the pitch.
He did not return to the field of play as Warren Gatland watched from the stands.
In the same game, Gloucester winger Louis Rees-Zammit had shown Gatland what he is capable of scoring twice and racked up more metres than any other player in the clash which saw Gloucester claim a 7-31 victory.
Lions Watch: Louis Rees-Zammit v Northampton 📊— Ultimate Rugby (@ultimaterugby) May 8, 2021
• 63 Minutes ⏰
• 2 Tackles 💥
• 0 Missed tackles ✖️
• 1 Turnover 🦾
• 2 Passes 🖐️
• 6 Carries 🏃
• 3 Defenders beaten 🕺
• 2 Clean breaks 💨
• 67 Metres (most) ⚡️
• 2 Tries 🔥#GallagherPrem #LionsRugby pic.twitter.com/5JjDKGkxgu
Speaking after the game Saint's coach Chris Boy spoke of Biggar's injury saying: "He's okay.
"He had that clash with Billy Twelvetrees and failed his HIA.
"He didn't seem to have any symptoms.
"We've got a bit of a longer week, not playing until next Monday (at Newcastle) so he's got plenty of time to hopefully recover."