Catalysis in confined spaces, such as provided by supramolecular cages, is quickly gaining momentum. It al-lows for second coordination sphere strategies to control the selectivity and activity of transition metal cata-lysts, beyond the classical methods like fine-tuning the steric and electronic properties of the coordinating ligands. Only a few electrocatalytic reactions within cages have been reported, and there is no information regarding the electron transfer kinetics and thermodynamics of redox-active species encapsulated into supra-molecular assemblies. This contribution revolves around the preparation of M6L12 and larger M12L24 (M= Pd or Pt) nanospheres functionalized with different numbers of redox-active probes encapsulated within their cavi-ty, either in a covalent fashion via different types of linkers (flexible, rigid and conjugated or rigid and non-conjugated) or by supramolecular hydrogen bonding interactions. The redox-probes can be addressed by elec-trochemical electron transfer across the rim of nanospheres and the thermodynamics and kinetics of this pro-cess are described. Our study identifies that the linker type and the number of redox probes within the cage are useful handles to fine-tune the electron transfer rates, paving the way for the encapsulation of electro-active catalysts and electrocatalytic applications of such supramolecular assemblies.