Middlesex have signed Ollie Rayner on loan from Sussex in a deal that will run until at least the middle of May.
The 25-year-old off-spinner will join his new team-mates at Lord's on his return from Namibia, where he is currently on tour with the MCC.
Rayner, who is second-choice spinner at Sussex behind England international Monty Panesar, will remain with Middlesex until at least mid-May.
Sussex cricket manager Mark Robinson said: "It's a good opportunity for Ollie to play some first-team cricket at a time of the year when the likelihood of playing two spinners is very slim.
"This should enhance his development and will be beneficial for both him and the club on his return."