Rob Lyon admits it was a head over heart decision to replace King's Lynn Stars' fans' favourite Kozza Smith with talented Brit youngster Richie Worrall.

The popular Australian has struggled in his side's first five meetings this term after returning from a year out of the sport with a broken leg.

Despite Lynn's outstanding start to the campaign, Lyon has moved quickly to make a change to his line-up – even though it was a decision he found hard to make.

The Lynn team boss said: 'It's been a very, very difficult call which hasn't been made lightly. My head has ruled my heart 100pc. Kozza's commitment is first class but it's not quite worked out for him. I am sure it will happen and he will get where he needs to be again but sometimes you can't always make popular decisions.

'I didn't want to knock his confidence further by just utilising him in rides where he was just filling in. I personally think maybe it was a bit too soon to be riding in the Elite League and now he can concentrate on his Premier League racing and consistently knocking in points.

'Speedway is a results business, like a lot of sports, and my job is to do what I think it best to help the team win matches and after a long chat with Kozza I think he understands.'

Smith, a Lynn asset, will continue to ride for Berwick while 21-year-old Worrall, who arrives on loan from Belle Vue, comes in to take his place at reserve alongside free-scoring Swede Seb Alden.

The highly-rated Englishman will make his debut in the Stars' televised meeting at Lakeside Hammers this evening – a club he left in the summer amid a series of claims and counter-claims about the reasons for his departure from the Arena Essex outfit.

Lyon said: 'I'm sure Richie will do a great job for us. He's a terrific talent who is excited to be here. He will certainly know he's welcome at King's Lynn and he's hungry to do well. We saw a snapshot of what he's capable of when he guested for Coventry and I'm sure he can score loads of points for us and make a big contribution to the team.'

The Stars, who have won four of their five Elite League meetings in 2013, will be without solid performer Simon Stead for tonight's clash – as well as tomorrow's home meeting with Poole Pirates – after he dislocated his shoulder while riding for Sheffield at the weekend. The Hammers also look set to be without one of their top performers, injured heat leader Davey Watt.

Lyon will be able to use all of his team members, apart from Niels-Kristian Iversen and Rory Schlein, to fill in for the Yorkshireman's rides.

Lakeside: 1 Peter Karlsson, 2 Kim Nilsson, 3 Lewis Bridger, 4 Piotr ?Widerski, 5 Rider/Replacement, 6 Richard Lawson, 7 Robert Mear

Lynn: 1 Niels-Kristian Iversen, 2 R/R, 3 Mads Korneliussen, 4 Nicolai Klindt, 5 Rory Schlein, 6 Seb Alden, 7 Richie Worrall