When asked at the NFL Scouting Combine whether or not Sanchez had shown sufficient improvement last season, Tannenbaum told "NBC SportsTalk" there is still room to grow.
"Not enough," Tannenbaum said, per ProFootballTalk.com. "Not consistently.
"You know, he needs to play better. The great thing about Mark is he'd be the first one to tell you that. We're excited he's our starting quarterback. He's done a lot of good things for us. He's won road playoff games. His rate of improvement has to keep going and get better, but we're excited about his work ethic and his commitment."
Sanchez completed 56.7 percent of his passes for 3,474 yards and 26 touchdowns while getting picked off 18 times in his third pro season, leading the Jets to an 8-8 record.
The Jets finished their season amid controversy and discord, with players criticizing Sanchez anonymously in a Daily News article, while another unnamed player called receiver Santonio Holmes "a cancer." Earlier this month, Ryan said Holmes wanted to spend time with Sanchez to better their relationship.
"Was our chemistry perfect? No," Tannenbaum said Thursday. "And we're looking at ways to clean that up, and we talked to a lot of players. ... But we have to assemble a better team. It starts with me, and it starts with this process here at Indy."