Pre-season has been a hard slog for Gordon Strachan, the Celtic manager. Results have been patchy and the lack of depth in his squad is alarming. Last night, though, he could at last allow himself a semblance of a smile as his patched-up team demolished Feyenoord, the host club, 3-1 to finish runners-up in the Jubileum tournament here.

It was only a semblance of a smile. Strachan may have been pleased with the win, only Celtic’s third in seven friendlies, but he knows full well that there is much work still to be done before their opening match of the Clydesdale Bank Premier League season, at home to St Mirren on Sunday.

Strachan and Peter Lawwell, the Celtic chief executive, will be working overtime over the next week to boost the strength of the squad. No greater was the problem illustrated than last night, when Strachan could name only six substitutes – seven were permitted – because of having to rest players, injuries to others and the dearth of new signings.

“Yes, our resources are a bit limited at the moment,” Strachan said. “That’s why we couldn’t fill the bench tonight. That’s how short we were. We’re trying to sign players and, believe me, Peter is very active at the moment. From the point of view of the players we have, I just hope that we can get a few more in.”

Strachan declined to identify his targets but Gabriel Tamas, the £3 million-rated Romania defender, continues to interest him. Whether he can prise him away from Auxerre, his French club, is another matter, especially as the clock runs down. Strachan would prefer to have him now, not for when their Champions League campaign starts next month.

Celtic had been poor in the 2-0 defeat against Tottenham Hotspur, also in the De Kuip Stadium, on Friday night. They hardly mustered a shot throughout, perhaps emphasising the gulf between the Barclays Premier League and their Clydesdale Bank cousins.

Strachan had not been impressed and, not for the first time, had bemoaned his lot. “We’re a bit threadbare right now,” he conceded, with an envious glance at the talent at the disposal of Juande Ramos, the Tottenham head coach. If only Strachan could sign the likes of Luka Modric and David Bentley.

A different day, though, a different display. Celtic sprung from the traps as if chasing a Dutch hare and were 3-0 up within 39 minutes against Feyenoord, who had lost 2-1 to Borussia Dortmund in their opening match. This time, Strachan’s mix-and-match selection hit the ground running.

Tottenham had cruised past Dortmund 3-0 earlier to win the tournament and Celtic opened in similarly swashbuckling fashion, with Georgios Samaras sweeping them ahead in the twelfth minute. Having cleverly chested down Paul Hartley’s free kick, he guided the ball home with expert ease.

Two minutes later, Aiden McGeady ghosted past three opponents, exchanged passes with Lee Naylor and crossed for Jan Vennegoor of Hesselink to glance in with his head. The Celtic fans who had endured such De Kuip dross on Friday were ecstatic.

It got better. McGeady was again the architect, six minutes before the break, and once Vennegoor had controlled his centre with aplomb at the far post, the rest was simple. Mark Brown, who replaced Artur Boruc in goal at half-time, may have had to make a series of agile saves in the second half – and was beaten by a 20-yard shot from Leroy Fer – but Celtic were good value for the win.

Still, Strachan urged caution. “The first half was good,” he said. “We play these games for our benefit, they’re not really about winning or about entertainment. We’ve got something from every [friendly] game, we’ve got good information, hopefully, for the rest of the season. But preseason can never ever tell you how your season will go. Never.”