Mark McGhee believes Motherwell's surprise Scottish Cup defeat to Dundee should spur them on in their challenge for third place in the SPL.His team have a point to prove after a poor showing in their 2-1 fifth-round defeat by the First Division outfit.

And a renewed hunger could be a positive influence as they bid to overhaul Dundee United in the table.

McGhee's side, who are 'away' to tenants Gretna on Saturday, are just one point behind their Tannadice rivals with three games in hand.

They would leapfrog United if Craig Levein's side slip up at Inverness while Motherwell defeat their groundsharing partners for the third time this term.

McGhee admits he and his players took several days to recover from last Monday's cup defeat.

He said: "I'd still rather it hadn't happened, but I think it will be a launchpad for the last part of the season.

"People will have seen that result and be wondering if we've hit a wall and if our small squad or the pitch will now start to cost us, and we have to show that we're still here and that we can keep going in the league.

"It's a massive incentive that if Dundee United slip up we can overtake them; we could be sitting in third spot on Saturday night, still with three games in hand over them, and that would be fantastic.

"The players are hurt following the cup game and there was a lot of disappointment in the immediate aftermath, not just from them but from me and Scott [Leitch, assistant manager] as well, so we all want to make sure that it's not some sort of malaise and that it doesn't happen again.

"It probably took us until Friday morning to get over it and to move on to what's an important game, but there's been a good response from the team and they've trained brilliantly since then."

McGhee promises the return of captain Paul Quinn and striker Chris Porter means his team "will be improved" for Saturday's league encounter, adding: "Missing them the other night cost us dear because I think if they had both played, we wouldn't have lost the way we did."

The Motherwell management team will occupy the away dugout against Gretna but the landlords will otherwise enjoy all the usual home comforts of a game at Fir Park, including changing in the home dressing room.

McGhee's team have won both of their previous matches against the basement side, who have still mustered just three top-flight wins since being promoted.

Gretna radically overhauled their squad during the January transfer window, and McGhee, who watched then lose 4-2 at Hibernian in midweek, said: "They have four or five new players still being integrated so we don't really know what to expect.

"They scored two goals the other night so they might think that's enough to keep the same team, but it's really about ourselves in any case.

"It's another really difficult SPL game and that's how we must approach it, but I think we need three or maybe even two wins for a place in the top six, and the quicker we get them, the quicker we can feel confident and then start to think about greater things.

"Our ambition would be to get some points on the board from playing Gretna and then Inverness on Wednesday to get above Dundee United before we play them next month and put ourselves in the position of making that game one that we don't have to win."

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