Former Dundee United defender David McCracken has finalised his move to St Johnstone in a two-year deal.
McCracken left Tannadice in 2007 for Wycombe after eight seasons at United before spells at MK Dons from June 2009 then a disappointing time at Brentford.
The 29-year-old centre-half made only two appearances for the Bees after joining them last summer.
But the Scotland Under-21 international played 10 games for Bristol Rovers on loan last season.
McInnes has lost the experience of centre-half Michael Duberry since the previous campaign but has signed defender Frazer Wright from Kilmarnock and former Dundee United midfielder David Robertson.
Meanwhile, after his loan spell from West Brom last season was cut short by a knee injury, Canadian striker Marcus Haber has returned to St Johnstone for pre-season training.