The Fir Park side had finished second twice and third in their three previous seasons but were toiling in the lower reaches when McDonald arrived in February.
The Australian striker found a team riddled with panic and uncertainty as the grim reality of the potential loss of top-flight football took hold among the players.
However, a rousing end to the campaign, climaxing in a resounding 6-1 aggregate victory over Rangers in the play-off final, convinced McDonald to sign on permanently once more on a one-year contract.
The 31-year-old said: “I was absolutely shocked when I first came back. I think there were panic stations and the boys were worried about what the future held. It was hard work to achieve what they achieved but they’ve always been looking down on everyone else and not looking up.
“If I’m being honest I don’t think if the club had gone down I’d have been back, it’s as simple as that. You want to play at the best level you possibly can for as long as you can.
“But thankfully everything went well at the end of last season. It was a stressful time, I didn’t think it was going to be that stressful but Ross County just kept winning and fair play to them.
“We proved in the play-offs against Rangers that we can do it on the big occasion but it’s important that we do that week in and week out.
“It’s alright doing it on a one-off basis but we’ve got to be more consistent. If you look at the form guides at the back end of last season we were well and truly in the top half of the table, so were Ross County, I think they were equal with Celtic. That showed you how hard it was to try and get out of the situation we were in.
“So it was a shock to the system but a reality check as well. Everyone doesn’t want that again and it’s all systems go.
“But we took a lot of confidence from that and the type of players we have here, we’ve got some exciting young players and a lot of pace in the team so we’ll look to build on that.
“Two new strikers have come in so if I can help them as much as I can I’ll try to do that and they’ll be successful and we all will.”
McDonald, whose first spell for Motherwell between 2004 and 2007 produced a goal every two games, had other more financially rewarding offers to continue his career. However, having made a good living from his time with Celtic, Middlesbrough and Millwall he was more than happy to re-sign for a club which he holds dear.
He said: “I looked at all my options over the summer before making my decision. It came down to what this club means to me and also what it brings to me. There’s the warmth that I feel when I step through the door and how I’m treated here was a big factor.
“I have a lot of special memories at Fir Park and I still have my house here so moving back was an easy option. We have another baby on the way, too and that was a massive factor as well. There were more lucrative offers on the table but I’ve been lucky enough to have had a decent career and done okay out of the game so this was more about me being happy again.
“It’s been a tough road in the last few years in terms of finding happiness in my football but I was really enjoying it again at the back end of last season. Being one of the senior players and being asked to take on extra responsibility was really nice and it was great to see young players doing well and Lee Erwin moving on. Hopefully, myself, the coaching staff and the other older guys can help our youngsters push on.”
This season is the 25th anniversary off Motherwell’s famous Scottish Cup triumph in 1990/91 and McDonald hopes it is an omen while recognising that stability in the Premiership is the main aim. He added: “It’s been a long time since Motherwell last won anything – it’ll be 25 years next season since they won the Scottish Cup – so we’re due a cup run. Obviously, it would be nice to mark that anniversary with another trophy but, as always, the league will be the priority.”
Motherwell’s pre-season preparations continued at the Energy Assets Arena last night with a 2-1 defeat by Preston North End. Joe Garner and Neil Kilkenny put the English Championship side two up at half-time at Livingston’s ground, before Lewis Moult scored his first Motherwell goal late on.