There were several teams in the SEC that really struggled offensively in 2015 and, as you would expect, several changes were made in the offseason because of it. That’s just the nature of the beast.

It’s a game played by players, of course, and more often than not, it’s the teams with the best players that win. But concepts, technique and motivation come into play too. There are five new offensive coordinators in the league and several position coaches.

Here are the three most important hires on the offensive end.

Josh Heupel, offensive coordinator, Missouri: This was an interesting hire by new Mizzou coach Barry Odom. Heaped, who’s only 37 years old, has an impressive resume. He won a national championship as a QB at Oklahoma in 2000 and was considered an up-and-coming coaching star there but he was abruptly fired after the 2014 season. He went to Utah State for a year, but he’s back where he belongs, in a more high-profile program.

He’s got his work cut out for him. Mizzou’s offense was horrible last year. Maty Mauk is back with the program, and if he can keep his nose clean, he will make Heupel’s job much easier. It’s nice to install a new program when you have a veteran QB. Drew Lock struggled as a freshman, but that was more because the lights were too bright than it was a lack of talent. This is one worth watching. “I believe this is a special place that has just scratched the surface of what it can be, and it’s a program that is capable of winning championships on a consistent basis,” Heupel said after his hire.

Sam Pittman, offensive line coach, Georgia: The was a bit of a shocker because the thought was that Pittman, who had done a great job with the O-line at Arkansas, was attached at the hip with Arkansas head coach Bret Bielema. That’s what Bielema thought, at least. His departure, but it sure made the folks in Athens happy. Pittman is that good.

Pittman will play a key role in getting that Bulldogs running game up among the elite. Georgia has a roster full of great running backs and with a solid offensive line, they should be tough to stop. Pittman and new OC Jim Chaney will work well together. His presence there will be closely watched, as well as what happens in his absence at Arkansas.

Kurt Roper, offensive coordinator at South Carolina: There were quite a few people who shook their head when South Carolina hired Will Muschamp to be their head coach, especially since it was fairly obvious that he failed during his four years at head coach at Florida. UF let him go mostly because his offense was unwatchable.

That’s what made Muschamp’s hiring of Kurt Roper as his offensive coordinator somewhat surprising too. It was Roper who ran that bad Florida offense the year they both got fired. Roper spent last year with the NFL’s Cleveland Browns and he, much like Muschamp, is really looking forward to a second chance in the SEC.

The three other new offensive coordinators are Noel Mazzone at Texas A&M, Jim Chaney at Georgia and Eddie Gran at Kentucky. Each inherits a unique set of problems. Mazzone will be breaking in  new quarterback but at least he has plenty of weapons at wide receiver. Chaney has a great staff, even beyond Pittman, but they need a quick turnaround. Gran has a head coach on the hot seat, so he needs to develop Drew Barker in a hurry.

All these guys will have plenty of eyeballs on them come the fall.