The Spanish midfielder's fine display at Deepdale was cut short when he was stamped on in a challenge with a Lilywhites defender. He hobbled to the sidelines for treatment late in the first half and did not reappear after the interval.
A nasty cut on the Basque star's instep required seven stitches, but it was the severe swelling and bruising which most concerned the Liverpool medical staff and manager Rafael Benitez.
Alonso has been hampered by a number of foot and ankle problems through his Anfield career, and it was initially feared he had suffered a reoccurrence of the metatarsal fracture which ruined his 2007-08 campaign.
However, scans taken yesterday have cleared the 27-year-old of any breaks or structural damage, and he is even a slim chance to feature this Saturday when the Reds take on Stoke City.
But most important for Benitez and his side is the fact Alonso will be available for the back-to-back derby dates with Everton. The Merseyside rivals will clash in the Premier League on January 19, before meeting in the FA Cup fourth round the following week.