The Sons lost their first game of 2012 on Tuesday, going down 2-0 to league leaders Cowdenbeath.
Alan Adamson's side now sit third in the Irn-Bru Second Division, seven points behind Arbroath, who they face at Gayfield tomorrow.
Grindlay said: "It's disappointing that the run has come to an end, but we have to focus on the positive.
"It was a great achievement to go ten games unbeaten. I think it has helped our confidence, and also made us stronger as a group.
"It's important to keep our heads up, because we're still in a good position. We're third in the table, and there's a lot to look forward to."
Dumbarton have played Arbroath three times this season, and the teams have shared a whopping 19 goals.
Paul Sheerin's side won the first encounter 4-3, before repeating the feat two months later.
The Sons eventually got their own back, beating their opponents 3-2 in January.
However, Grindlay is hoping to keep it tight tomorrow. He said: "I'm the same as every other keeper. I pride myself on clean sheets, and want as many as possible.
"The games against Arbroath are usually pretty lively. They've been exciting, especially for the fans.
"I don't really care whether it's 4-3 or 5-4, so long as we get the win.
"But a shut-out would make it extra special, and that's obviously what I'm aiming for."
Elsewhere, Albion Rovers host Airdrie United in the fourth Monklands derby of the season.
Airdrie have won two of the meetings, but Rovers destroyed their rivals 7-2 in November.
Paul Martin's men also defeated Stenhousemuir on Tuesday – their first win in almost three months – and currently sit four points behind their opponents.