Upper Dublin has won its seven games, including four in the Suburban One League American Conference, by a combined score of 274-93.
"I don't think we expected to come out of the chute that strong," Siwinski said. "Beating Central Bucks West in our opener was a big confidence booster."
The 6-foot-3, 180-pound Siwinski, a second-year starter, has a team-high 26 receptions for 399 yards (15.3-yard average) and a touchdown.
In Upper Dublin's 6-4 campaign last year, after missing his sophomore season because of a back injury, Siwinski acknowledged he was "a little timid" in his pass-catching role.
"I was a bit apprehensive when it came to running after the catch," said the 17-year-old, a midfielder in lacrosse. "That's not an issue now. I don't mind getting hit. I'll go for the extra yardage."
Derr, who last season threw for 876 yards and 12 TDs, has completed 52 of 91 passes for 667 yards and two TDs. The 6-3, 205-pounder has rushed 62 times for 529 yards and six TDs.
"Running is what he does best," Upper Dublin coach Bret Stover said.
"His brother is more of a natural thrower. We made the mistake last year of trying to make John a passer. That wasn't fair to him."
In the 45-21 romp over C.B. West, Derr turned six carries into 169 yards and two scores before leaving with a separated shoulder.
"He's so strong," Stover added. "When things break down, he makes things happen with his feet."
The Cardinals offense also features tailback Kaleif Lee (61 carries for 440 yards, 9 TDs) and fullback John Lee (65 for 415, 9). The two are not related. The line is anchored by center Patrick Echevarria, tackle Tyler Berish, and tight end Marc Conran.
A defense with a bend-but-don't-break mentality is headed by linebackers John Lee, Henry Winebrake, Jack Rapine, and Tim Rasmussen.
Ben Gause and Tamir Bailey lead the charge up front.
The future also looks bright for Upper Dublin, as five sophomores and three juniors are prominent contributors this season.
"The other thing we have this year is depth," Stover said. "When we have to turn to our bench, there's not the significant drop-off there was in years past."
Upper Dublin likely will battle defending champ Plymouth Whitemarsh (5-2, 4-0) for the American Conference crown on Oct. 25.
Cancellation. Mastery Charter North will be idle this weekend after learning that its scheduled opponent, the SEED School (Md.), will not make the trek to Northwest Philly for a Saturday afternoon game.
"It's very disheartening," Pumas coach John Davidson said. "I was told they're not playing because of academic ineligibility. I finally heard back from somebody after reaching out to them for the last 21/2 weeks."
SEED is a public boarding school in Southwest Baltimore that opened in 2008 and serves at-risk students.