After nine matches the Glovers sit in sixth position in Sky Bet League Two and head to Crawley on Saturday (3pm) looking to record a fourth straight win away from home.
The recent 6-0 win over Newport County was the club’s biggest victory since entering the EFL and marked Donnellan’s return from a thigh injury.
The Republic of Ireland Under-21 international limped off at half-time of the 2-2 draw with Mansfield at the start of August and missed the following nine matches.
Now back in action, Town’s defender is looking to remain grounded.
“Us as players, we’re taking each game as it comes,” he told iFollow Glovers. “We don’t want to look too far ahead, we’re just looking to Saturday – I know that’s quite cliché but that’s how we’ve got to look at it.
“You can’t get carried away because football changes so quickly and you have to stay level-headed, otherwise it won’t work out.
“Every game in this league is tough and every game is a new challenge. We go to Crawley well prepared and we want to go and get the three points.”
Donnellan completed his first 90 minutes since returning from injury in the 1-1 draw with MK Dons on Tuesday night.
Despite competition for places in the heart of defence, the 21-year-old is only focused on the continued success of the team.
“When the team’s doing well you can’t complain and that’s what I want and what every player in this team wants.
“It’s not about us it’s about the team, so as long as the team is doing well we’re all happy.
“On a personal level, I want to carry on where I left off. I felt on Tuesday I was getting my sharpness back, so I want to build levels back to where I was.”