The Falkirk West SNP representative is one of the original MSPs having been elected in 1999.
The first minister was speaking after SNP MPs put their names forward to stand at the 2026 Holyrood election.
The former health secretary was barred for 27 days after racking up an £11,000 data bill on his work iPad.
Former health secretary is serving a record ban for breaching MSPs code of conduct over the £11,000 bill.
The former health secretary was banned from parliament and docked pay over the scandal.
The former health secretary - who racked up an £11,000 data bill - will not be paid his salary for 54 days.
First Minister John Swinney has told BBC Scotland News he won't back sanctions against former health secretary Michael Matheson.
It comes after the SNP indicated they would not oppose the sanctions over an £11,000 data bill.
A Holyrood committee has recommended the former health secretary be suspended from parliament for 27 days.
