Stevenage will go into the League One season without top scorer Jamie Reid.
The striker has been diagnosed with "a medical condition" and will not be available for manager Alex Revell when Boro kick-off their year at home to Shrewsbury Town on August 10.
A statement from the club said: "Stevenage Football Club has confirmed that Jamie Reid has a medical condition that is expected to keep him out of first team contention for a while.
"The condition was discovered following his return from international duty with Northern Ireland and it’s expected that the 30-year-old striker, who scored 21 goals last season, will miss the opening month of the season."
The club have added that the problem was caught early and there was a confidence that the recovery shouldn't be overly complicated.
Reid was in the stands during Boro's 2-2 draw with Watford on Saturday.
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