Dowson made his very first Premiership appearance for Newcastle Falcons against Gloucester in November, 2001, and he will celebrate a special milestone at Franklin’s Gardens this weekend.
The 32-year-old will once again lead Northampton in the absence of club captain Dylan Hartley, who is on England duty.
And Jim Mallinder says Dowson deserves all the recognition that will come his way.
“Phil has been a leader and a senior figure throughout his time at the Saints, and I had plenty of respect for him when he was at Newcastle, too,” said Mallinder.
“Passing the 200-appearance milestone in the Premiership is pretty rare, and reflects Phil’s consistency throughout his career.
“He sets himself the highest standards and is a great example for the other players at the club. “Phil certainly deserves all the congratulations that will come his way tomorrow.”
Dowson captains a side that sees two changes from the 22-16 victory at Newcastle Falcons last time out, with Mallinder opting to shuffle his pack.
Alex Waller and Samu Manoa are both left on the bench, with Ethan Waller and GJ van Velze taking their place in the starting line-up.
England duo Lee Dickson and Ben Foden are part of a strong replacements list, which also includes Tom Mercey, who, like Foden, makes his return from injury.
Saints: Wilson; K Pisi, G Pisi, Stephenson, Elliott; Myler, Fotuali’i; E Waller, Haywood, Ma’afu; Dickinson, C Day; Clark, Dowson (c), van Velze.
Replacements: McMillan, A Waller, Mercey, Manoa, Nutley, L Dickson, Hooley, Foden.
Gloucester: Cook; Sharples, Trinder, Tindall (c), Thomas; F Burns, Robson; Thomas, Edmonds, Harden; Stooke, Hudson; Kalamafoni, Kvesic, Evans.
Replacements: Dawidiuk, Murphy, Puafisi, James, Cox, Cowan, B Burns, Monahan