Stafford, 32, has two years remaining on his contact with the NFC North franchise.
Holmes met with reporters for his introductory news conference Tuesday and commented on the quarterback.
"Matthew is a great player," Holmes said. "I think the talent level is easy to see, but you really appreciate how his intangibles show on film, how urgent he plays, how competitive he is and the toughness that he shows.
"But it is my job to evaluate the entire roster, and through that process, I have not had any discussions with Matt or any players, for that matter. So I just want to be fair to the process and make sure that we evaluate that thoroughly, but obviously Matt is very good football player."
Stafford completed 64.2% of his throws for 4,084 yards, 26 touchdowns and 10 interceptions in 16 starts this season for the 5-11 Lions.
The 2014 Pro Bowl selection was off to a spectacular start in 2019, with 19 touchdown passes and five interceptions through eight games, before he sustained a season-ending back injury.
Stafford finished his 2020 campaign amid rib, ankle and thumb injuries. The 12-year veteran has a $9.5 million base salary in 2021 and has a $33 million salary cap hit.
The No. 1 overall pick in the 2009 NFL Draft is the Lions' franchise leader in passing yards and touchdown passes. Stafford threw a career-high 41 touchdown passes in 2011.
The Lions hired Holmes last week after the franchise fired head coach Matt Patricia and former general manager Bob Quinn in November. Holmes and the Lions will be hiring a new head coach.
The Lions have the No. 7 overall pick in the 2021 NFL Draft.