MELBOURNE ruckman Max Gawn says he feels pressure to return to his best in 2018 as he prepares to test his streamlined physique against St Kilda nemesis Billy Longer on Thursday night.

Gawn lost eight kilograms over the off-season in an effort to get as fit as he could and run out games better, believing he was shown up by some opponents in a 2017 season interrupted by a serious hamstring injury.

Despite adding some of that weight back onto his 208cm frame since, the 2016 All Australian said he would not know if his new physique would cut it in the bash and crash of an AFL season until he took on some hardened opponents.

"We've got two 19-year-olds at the club, who are developing very well, but they probably don't give me that test that an (Aaron) Sandilands would," Gawn said on Sunday. 

"I had (Todd) Goldstein in JLT round one and Goldstein is obviously a premier ruckman over the 100kg mark. 

"To have that test with the new weight was something I needed and this week I've got Billy Longer, who I've had some problems with in the past. 

"I'm sure he's going to test me out as well."

Gawn said his performance against Goldstein showed his fitness regime over the off-season had been beneficial and he had been covering the ground well late in the game. 

After missing 10 matches because of a hamstring injury last season, the 26-year-old said he felt "a little bit of pressure to get back to some form".

"I was in some pretty poor form last year, including my hamstring (injuries)," Gawn said. 

"I think we saw in 2015 and 2016, I stayed injury free for those two seasons and played the majority of those games to a relatively good level.

"Last year, I'd like to blame it on my hamstring, but I probably came back a little bit unfit and was just struggling to keep up with some premier ruckmen … they were running me around towards the end of the season." 

Melbourne completed roughly an hour's worth of match simulation at Casey Fields on Friday and will take on the Saints at the same venue on Thursday night before an 18-day break leading into round one.

Gawn said he expected the team to complete more match simulation training in that break ahead of its season opener against Geelong at the MCG on March 25.