The 26-year-old goes straight into the team to face Nottinghamshire in the Royal London Cup after penning professional terms
Leicestershire have signed left-arm seamer Michael Finan on a two-year deal following a trial period.
The 26-year-old, who came through the Lancashire youth system, has mainly been playing for National County side Cheshire.
He has played second XI cricket for Northamptonshire and Yorkshire, his most recent outing coming last month in the one-wicket win over Derbyshire.
Finan goes straight into Leicestershire's plans and has been named in the team to face Nottinghamshire in the Royal London Cup on Saturday (August 20).
The arrival comes after South African seamer Beuran Hendricks left the club to join Southern Brave in the men's Hundred, as a replacement for Craig Overton.
"I'm extremely excited to be here," he said. "It’s materialised very quickly and perhaps a bit unexpectedly, but I'm looking forward to getting stuck in.
Chris Wright has taken 19 wickets in the County Championship but lacks support (Stu Forster/Getty Images)
"The lads have been really welcoming. I know how well they're playing at the moment, so it’s about making sure I keep my standards up to their standards."
Leicestershire have endured a rotten red-ball season. The are winless from 10 games and sit bottom of LV= Insurance County Championship Division two heading into the final month of the season.
Central to their struggles has been a lack of wickets from their pace attack - none of them have reached 20 for the campaign - with Chris Wright inevitably leading the way with 19 at 43.89.
"Mikey's a really exciting prospect," said head coach Paul Nixon. "He's a strong character, who wants to get in the battle, and that’s exactly what we need.
"He's a guy who's got great pace, with the potential to get stronger and even quicker working with Alfonso Thomas, so we see a high ceiling."
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