New Swans Jed Lamb, Luke Parker and former Eagle Matthew Spangher joined the club for the first time on Monday morning, looking on as the majority of the senior list ran a 3km time trial.
Longmire, in his first pre-season as senior coach, said the ability of Lewis Jetta, Gary Rohan, Sam Reid and Trent Dennis-Lane to play senior footy in 2010 showed that anything was possible for the newcomers.
"What we learned from last year is not to put a ceiling on them. When we look at last year's five picks, four of them played," he said.
"We don't want to say they can or can't play; we'll just see how they develop."
Lamb, who was taken at No.21, attracted the Swans' attention for his obvious flair around goal but also his potential as an on-baller.
"He can win his own footy, he can obviously play forward and kick goals but we think he can also go through the midfield as well," Longmire said.
"We just think he's got some special attributes that AFL footy needs."
Parker was something of a slider when he was taken at No.40, having been regarded as a potential first-round pick after a strong TAC Cup season with the Dandenong Stingrays and a fine performance at the NAB AFL Under-18 Championships.
An outstanding runner with good leadership potential, Parker would fit in well with the club's penchant for strong inside midfielders, Longmire said.
"It's worked pretty well for us over the years. We've got some good mentors; we lost one last year in Kirky but we've still got a couple of hard nuts around the place who I'm sure will be happy to show them the way," he said.
Spangher (pick No.73) will bolster the Swans' key defensive stocks immediately while Longmire said Alex Johnson, a 194cm key position player from the Oakleigh Chargers selected at pick No.57, would take time to develop.
While the new draftees watched from the sidelines, rookie draft prospect Eugene Kruger led the main group home in the 3km time trial, followed by Nathan Gordon, Rhyce Shaw, Nick Malceski and Ben McGlynn.
Longmire said the majority of the squad had returned to training in good condition, with very few players sidelined through injury.
Dan Hannebery and Jesse White were among those not taking part as they recovered from off-season shoulder surgery. Ryan O'Keefe (groin/hernia) was also absent, Craig Bird ran laps and Ted Richards took part in light drills with the new draftees.
Craig Bolton (achilles) and Mark Seaby (ankle) were also missing as they continued recovering from injuries that ended their 2010 seasons.
