Under Sparano's guidance, second-year tight end Jason Witten flourished into a Pro Bowl talent while enjoying a record breaking season in 2004. Witten established Cowboys records for receptions (87) and receiving yards (980) by a tight end while finishing the year second in the NFL in receptions among tight ends and second in the NFL in receiving yardage for tight ends. The season ending injury to Dan Campbell in Week Three forced Witten's acceleration into the spotlight, and also forced Sparano to develop depth with youngsters Brett Pierce and Sean Ryan.
In 2003, Sparano's first season in Dallas, the Cowboys tight end corps became a dependable weapon in the team's running and passing games - helping the club improve from the 30th ranked offense in 2002 to 15th in 2003. Witten finished fifth among rookie receivers, first among rookie tight ends, with 35 receptions for 438 yards. Campbell continued his rise as one of the NFL's premier blocking tight ends while also catching 20 passes for 195 yards.
As the tight ends coach for Jacksonville in 2002, Sparano mentored Kyle Brady, who hauled in 43 passes for 461 yards and four touchdowns, the second-best numbers in each category for his career. In addition, Pete Mitchell grabbed 25 passes for 246 yards and two scores. Sparano's troops were also responsible for a Jags running game that averaged 4.6 yards-per-carry - fifth in the NFL - led by Fred Taylor's 1,314 yards.
Sparano spent the 2001 season as tight ends coach for the Washington Commanders. In 1999 and 2000, he was an assistant with Cleveland, his first season as offensive quality control coach before taking over the offensive line in 2000. From 1994 to 1998, Sparano was the head coach at the University of New Haven, where his teams made two trips to the NCAA Division II playoffs, finishing second in 1997. He was named the New York Metropolitan Football Writers Division II Coach of the Year and was the New England Football Writers Division II/III Coach of the Year in both 1995 and 1997.
Sparano began his coaching career at New Haven in 1984, spending four seasons as the offensive line coach and recruiting coordinator. He was the offensive line coach, recruiting coordinator and academic liaison at Boston University in 1988. From 1989 to 1993, he was BU's offensive coordinator, helping the Terriers to an 11-0 mark in 1993.