Boyd Rankin will become the first Irishman to play county cricket as an overseas player after signing for Derbyshire for the remainder of their Vitality Blast campaign.

Irish players had previously counted as local players in county cricket, but after their ascent to Test status anyone playing international cricket and signing a new contract will count as an overseas player.

Rankin, the 6ft 8in fast bowler who has played international cricket for both Ireland and England, will be available for Friday night's game against Northamptonshire.

Players were able to honour existing contracts until the end of this season - like Paul Stirling and Tim Murtagh, for example - but from next year will count towards overseas quotas. Counties are currently allowed to field one overseas player in the County Championship and the Royal London Cup, and two in the Blast.

The change in regulations may have wide-reaching implications for Ireland.

For example, Murtagh, who took five wickets in a brilliant new-ball spell against England last week, remains undecided as to whether he will choose to play for Ireland, or instead extend his contract as a local player.

"It's getting to the stage where we have to choose one or the other and I haven't really made my mind up yet," he told the Wisden Cricket Weekly podcast.

"There are still discussions to be had with both sides but unfortunately that loophole has been shut and we can't continue playing in county cricket as local players.

"I'm going to have to make quite a tough decision at the end of the summer and decide which way I want to keep going."

Rankin will become the first England Test cap to play for Derbyshire since Rikki Clarke in 2008 when he makes his debut.

He had previously played for the club in 2006 and 2007, before a spell with Warwickshire that saw him win England selection.

Dave Houghton, Derbyshire's head of cricket, said: "We have been looking for an additional fast bowler to strengthen our current squad for the T20.

"Boyd has international experience and will fit in well with the bowlers that we already have. With the pace and bounce that he generates, he will bring a new dimension and give us that bit extra."