With Strikeforce about to embark on their ambitious heavyweight grand-prix over an eight month period they are required to have several reserves in place in the unfortunate event that one of the eight stars who will features become ill or injured.

Therefore two reserve bouts have now been announced. The first sees two of the promotion’s most promising up and comers from the Challengers series, Shane Del Rosario and Lavar Johnson squaring off.

Del Rosario had been expected to be upgraded to a major Strikeforce event after producing a perfect 10-0 record to date. Only one of his fights has so far gone beyond the first round, and if he was called into action during the tournament he’d certainly be no pushover.

His opponent Johnson suffered a few losses early in his career, but has since produced a seven fights winning streak, three of those in the Challengers series, to take the hard-hitting striker’s record to 15-3.

The second pairing sees veterans Valentijn Overeem and K-1 fighter Ray Sefo locking horns.

Valentijn, brother of Strikeforce heavyweight champion Alistair has over 50 professional fights to his name, though he’s not enjoyed the same success as his sibling, going 28-25 during the past 15 years. He fought twice in 2010, winning both times by first round KO.

Finally, 39 year-old Ray Sefo is a seasoned veteran of K-1 holding a 56-21-1 record, but has also tried his hand at MMA twice in his career, winning on each occasion. He’s also 5-1 in boxing, having had his first bout some 16 years ago.