Lee Barnard was rushed to hospital with a suspected broken collar bone and Jamie Slabber was withdrawn within minutes of replacing Barnard with a shoulder problem.
The injuries certainly took the shine off another decent work out for a younger team against a tough Trollhattan outfit.
Mendes stroked the ball around impressively in a 35-minute stint in the second half and Fulop was mainly untroubled.
The Hungarian U21 international could do nothing about Trollhattan's winning goal as Kristoffersson raced onto Hultberg's long pass before sliding the ball into the bottom corner.
We had a few shots from distance in the first hour - a Stephen Kelly blaster stung Wennergren's hands - but our best moments followed Robbie Keane's arrival alongside Stephen Carr in the final quarter.
Larsson, in goal for the second half, tipped over Keane's free-kick before three chances in the final few minutes.
A somewhat lucky bounce from Michael Malcolm's tackle sent Keane clear three minutes from time but although the Irish star left Larsson for dead, he ran the ball out of play.
A minute later and Keane was through again from Rohan Ricketts' delightful chip over the top but his attempted lob landed on the roof of the net.
The last action came in the final minute as Larsson could only palm out Mendes' sweet strike from 25 yards.
Guide to the action
6mins: Yeates spread play from right to left, McKie and Ricketts combined to set up a Hughes 20-yarder that went over the bar.
8mins: Deep Kelly cross picked up by Ricketts, low shot gathered by keeper Wennergren.
10mins: Marney's free-kick from 25 yards skipped up, but Wennergren saved well.
15mins: Kristoffersson's 20 yard shot easily taken by Fulop.
17mins: Kelly 30 yarder stung Wennergren's hands, but the keeper held on.
32mins: Barnard into tackle with Andersson, laid motionless and stretchered off with what looked like a shoulder injury. Jamie Slabber on as replacement.
38mins: GOAL Kristoffersson onto Hultberg long pass, slid ball past Fulop. 0-1.
43mins: Yeates rolled ball back to Ricketts, low shot saved by Wennergren diving to his right.
44mins: Excellent cross by Marney from right touchline, Slabber and Hultberg both stretched for ball, Slabber reached it, but couldn't keep effort down from eight yards.
44mins: Slabber stayed on ground after the chance, was led off pitch also holding his arm and replaced by Michael Malcolm.
Half-time: Trollhattan 1-0 Spurs
55mins: Pedro Mendes comes on for his Spurs debut in place of Sean Davis.
62mins: Marney onto defence splitting pass from Mendes, controlled it well but couldn't get enough on his shot.
63mins: Mendes shot from 25 yards flew over the bar.
69mins: Keane and Carr on for Kelly and Marney.
80mins: Keane free-kick tipped over by Larsson.
87mins: Kind bounce from Malcolm tackle sent Keane through on goal. Took ball around Larsson but ran the ball out of play.
88mins: Ricketts chipped ball through to Keane, through one on one, lobbed chance onto roof of net.
89mins: Mendes cracker palmed out by Larsson.
Full-time:Trollhattan 1-0 Spurs
Spurs: Fulop, Kelly (Carr 69), McKie, Mabizela, Doherty, Marney (Keane 69), Hughes (O'Hara, 45), Davis (Mendes 55), Ricketts, Yeates, Barnard (Slabber 32, Malcolm 44). Subs: Ifil, O'Donoghue, McKenna, Burch.
FC Trollhattan: Wennergren (Larsson), Olsson, K Karlsson, Hultberg, Andersson, Nilsson, Holmqvist, Mohemmedian, Eriksson, Kristoffersoon, R Karlsson.
Pedro Mendes and Marton Fulop made their debuts but injuries overshadowed the third and final friendly of our Swedish training camp against Trollhattan on Saturday.