The 18-year-old had been on the pitch just 30 seconds when he lost his footing and suffered a leg break.
Under 19 midfielder Sweetnam, who has been on the fringe of the first team this season, told the Guardian of his bitter disappointment.
“We had a throw in and I ran to get the ball to feet and slipped, all my weight went on my left leg and I heard it go,” he said.
“It was horrible.”
“They took me in an ambulance to Kings Mill hospital for a couple of X-rays and told me it’s a Category C fracture, so the fibula is in place but it’s broken.”
North Notts College student Sweetnam’s frustration at the injury is undestandable, having finally been given a chance to show off his ability in front of first team boss Simon Clark.
“I’ve been enjoying it at the club, but I’ve been on the bench for about eight games and when I get on the pitch I break my leg.”
“It’s so disappointing, but hopefully I won’t be out too long and I can get back in this season.”
The incident was tinged with irony, as Sweetnam came on to replace Matt Young, who is making his own return from a broken leg suffered in a pre-season friendly.
Young knows exactly how the teenager is feeling, and offered words of support.
“It’s gutting for him, he’s a young lad trying to make his way into the game but I’m sure he’ll come back fine,” said the former Huddersfield Town midfielder.
“It’s a hard three months trying to get yourself fit, but it’s one of those things that can happen when you play a contact sport.”
Young was one of a number of players getting some valuable match fitness under their belts, in a game Tigers won 1-0.
He was pleased with his return to the pitch. “I got a bit of cramp in both calves near the end, but I was happy with the minutes I played,” he said.
“I got stuck into a couple of tackles with my weak leg and it came through unscathed, it was a good workout for me.”
Centre-half Jack Hutchinson got the goal in the first of three 30-minute periods of play, nodding in Owain Warlow’s corner.
Several Under 19 prospects got a run out, along with first teamers including new goalkeeper Jan Zolna.
Worksop Town: Zolna, Gardner, Turner, Young, Hutchinson, Roberts, Duncum, Fox, Davidson, Muller, Warlow. Subs (all used): Wood, Whitwell, Sweetnam, Alali, Lowder, Payne, Taylor.