Tom Sykes has admitted his return to action with Yamaha Italia was 'tough' after being struck down by a bug that forced him to miss half of the test at Kyalami.

Looking to get more miles on the Yamaha R1 under his belt, Sykes managed just 16 laps on the first day before deciding to sit on the sidelines in recovery.

Although he didn't return to the circuit until half-way through the second day, Sykes made steady progress until the end of the test, eventually emerging with the 12th quickest time.

Despite being 1.6secs adrift of team-mate Ben Spies, an ailing Sykes was pleased with the progress made and hailed the efforts of the Yamaha team for improving the bike every time he went onto track.

“It's been a tough test! I missed one and half days through this bug I've had so was a long way behind with laps. When I got out I still managed to get some good laps in and the team were brilliant, they improved the bike massively every time I came in. I've got a very sore shoulder from falling today but it's nothing serious.”