Sims not only ranked third in catches with 36, but also with receiving yards with 475. He also was arguably the biggest threat in the passing game in 2012.
"I don't know if you replace (the production of Sims)," co-offensive coordinator Jim Bollman said. "I think the overall offense has to come — I don't know if anyone specifically will take that — and improve.
"We especially have to improve in the passing game. Specifically, (Sims) was a gifted individual." It will be hard to fill, but sophomore Paul Lang believes it was a blessing to watch and learn from Sims.
"Dion definitely set the bar high for us, which is great because we can learn off that," he said. "Being under his belt last year and being able to watch him play definitely helped, but us as a tight end unit (we) had a really strong spring and summer.
"We just have to be consistent as the fall goes on and be ready for first game against Western Michigan."
Lang learned a lot last year from Sims, as he stepped in the Michigan rivalry game and score the lone touchdown among the tight ends.
"That was a great opportunity — Dion was battling some injuries last year — and I was put in a situation where I was wide-open in the end zone so I got the ball thrown my way," Lang said.
The outcome wasn't what the Spartans had hoped for, but it's a glance in the near future for the young tight ends.
"Unfortunately, we came up short that game and that really threw everything away because losing to Michigan is not the best feeling — it rips your heart," Lang said. "I would've definitely taken the win over a touchdown."
Based off this offseason, junior Andrew Gleichert feels the tight end unit can fill the void left by Sims.
"I think the biggest thing — through production on offense — is passing yards," he said. "Dion had a lot. Me and Paul make that up of what we lost."
Bollman said he is not worried of the young tight ends' receiving skills.
"They're much more than adequate receivers," he said. "That's not a concern of mine at all. I think they'll be pretty good that way."
Sophomore quarterback Connor Cook said the pair of Gleichert and Lang are having a good camp so far.
"Gleichert is doing a great job and so is Paul Lang," he said. "They are both working with the ones and twos. Gleichert is showing tremendous running ability, getting open and catching the ball and not having any drops. Same thing with Paul. Paul has getting open and catching the ball when the opportunity presents itself. I'm just happy for the both of them."
It isn't just about the pass catching, though, and Gleichert said he knows the coaches have a blocking focus, and without it, they won't see playing time.
"I'm a blocker, too, and Coach Bollman says ‘we're not going to get on the field till we can block.'" Gleichert said. "You got to block as a tight end."
Bollman knows that the Spartans regularly have a dominant run game, which will require good blocking from the tight end position.
"They're really working hard at their technique to be proficient at things," Bollman said. "I think they keep doing the things the way they are and the way they did it in spring they'll become pretty good blockers.
"We've always been a good running team. We have to continue to be a good running team. We won't improve our passing game as much as we need to if we suffer in the running game. So, we have to do that and the tight end spot causes a lot of variations and deviations in what kind of runs you're going to do."
Lang said that he and Gleichert worked out together over the summer to get better at their blocking techniques.
"We joined together and did drills together because we are putting a big emphasis on blocking," Lang said. "We're doing a lot of blocking with our hands, which takes a lot of concentration.
"That's been our main focus and we've also been able to run routes with the quarterbacks and receivers to improve that aspect of it, too."