Blackburn Rovers' South Africa striker Benni McCarthy was to have further tests after collapsing on the pitch at the weekend, Sky Sports News television reported.
McCarthy was released from hospital and travelled back to Blackburn with the team Saturday after the incident during his side's 2-1 away win over Middlesbrough at the Riverside.
The forward clashed heads with Boro defender Chris Riggott during a second-half challenge.
McCarthy then collapsed as he spoke with Blackburn's physio.
After several minutes of treatment on the pitch, the striker was stretchered off wearing a neck brace and taken to hospital.