Tomicek previously raced for the Oxford Cheetahs

Lakeside Hammers rider Lubos Tomicek has been ruled out of action for ten days with concussion.

Tomicek crashed in Sweden a week ago and could now miss up to five meetings.

The Czech rider was already set to miss Wednesday's meeting with Belle Vue but will now also be absent for the Hammers' trip to Ipswich on Thursday.

Team manager Jon Cook said: "Losing Lubos for Ipswich is another blow as it's one of his better tracks, but we have a good deputy in Kauko Nieminen."

Kings Lynn's Tomas Topinka will ride in place of his countryman against the Witches.

We need to be positive and look at the fact that all our remaining meetings are very winnable Jon Cook

And Cook added: "Provided Lubos can get back for our meeting on the 19th against Peterborough then no damage should be done to our aspirations."

Tomicek's enforced absence has come in the wake of long-term injuries to Adam Shields, Joonas Kylmakorpi and Jonas Davidsson.

And it leaves the Hammers with only three of their regular riders available for this week's two meetings.

Despite the latest setback Cook added: "We need to be positive and look at the fact that all our remaining meetings are very winnable and a finish in top spot is now not out of the equation."