The Hatters skipper was tracking back to defend during the sixth minute of the game at Wembley, when he collapsed to the pitch under no pressure from any rival players.
Lockyer received several minutes of treatment from both clubs’ medical teams and was given oxygen before being stretchered off.
Sky Sports reported later during the first half that the 28-year-old was conscious in the medical room at Wembley, with his parents coming down from the stands to be with him.
Sky then reported at half-time that Lockyer was still conscious and stable and had been transported to hospital.
Luton have now confirmed those reports, announcing that Lockyer had indeed been taken to hospital for tests. They also said he was responsive and talking to his family.
“We are able to report that after collapsing on the pitch, Tom Lockyer has been taken to hospital for further tests,” Luton said in a statement.
“He is responsive and talking to his family, who are with him. We are all with you, Locks.”