In addition to being aired locally on Fox Sports Arizona, the Dec. 22 contest will also be shown on NBA TV.
The Suns beat the Trail Blazers at home 114-87 on Wednesday to improve to 5-7 on the season. Their meeting next month will be played at the Rose Garden.
The two teams will meet three times this year with the third game coming on Feb. 19 in Portland.
The 5-6 Trail Blazers are in last in the NBA's Northwest Division, but are just 3½ games behind the first place Oklahoma City Thunder. Phoenix is in fourth pace in the Pacific Division, 3½ games behind the Los Angeles Clippers.
The Suns host the New Orleans Hornets Friday night at 6 p.m. PST.