Division Two leaders Northamptonshire lost captain Stephen Peters for up to six weeks with a broken finger before reaching 91-4 against Leicestershire.
Peters suffered the injury during a morning net session, meaning he was replaced in the side by 21-year-old Rob Keogh.
In the 34 overs that were possible between showers, some loose shots by the Northants top order saw them lose four wickets, as Leicestershire paceman Ollie Freckingham took 2-34.
Leicestershire made an early breakthrough when James Middlebrook sliced Freckingham to Jigar Naik at gully after making just two.
While Middlebrook was trudging back to the pavilion, the heavens opened yet again leaving the players with another sprint for shelter.
Play got under way again at 4:45pm and Northants soon lost David Sales cheaply for 10 when he was taken by Naik at gully off the bowling of Alex Wyatt.
Leicestershire brought on Robbie Williams in the 17th over and he claimed the wicket of Matthew Spriegel, who chipped him to Matthew Boyce at square leg to perish on 11.
Stand-in captain Alex Wakely made 18 before he was next back in the pavilion when he dragged Freckingham on to his off stump.
Rob Newton and former South Africa international Andrew Hall were then able to see out the remaining 10 overs and will resume on 22 and 12 respectively.