Higdon is joint top-scorer in the Scottish Premier League with 19 goals, alongside Inverness forward Billy McKay and Leigh Griffiths of Hibernian, who visit Fir Park on Friday night.
Ojamaa only has two goals this season but he is joint top of the SPL assists table with 12, a position he shares with Caley Thistle winger Aaron Doran.
Ojamaa said: "It speaks volumes for the team and our attacking performance when Higgy is top goalscorer and me and Doran are top assists.
"That shows how good we are going forward and how well we have done this season. It's a credit to all of us.
"Michael has had a great year. It's a great fit with Michael.
"I think his first-time finishing is definitely the best I have ever played with.
"With the flair players we have around him such as myself, Nicky Law, Chris Humphrey, we had Murph (Jamie Murphy) before and now we have Faddy (James McFadden), Kallum Higginbotham, everybody can really complement him and create chances for him and he is just great at putting them away.
"We are very lucky to have him and he has had a great goalscoring season."
Victory over Hibs would put second-placed Motherwell five points clear in second place with their closest rivals Ross County and Inverness meeting on Saturday.
And Ojamaa is looking to extend Motherwell's lead ahead of the the split with games against Dundee and St Mirren to follow.
Ojamaa, who has been called up to Estonia's squad for World Cup qualifiers against Holland and Andorra, said: "It's really important that in the last eight games we really go into the next gear and finish strongly because it's still very tight.
"After the split there are going to be some very tight games and I'm expecting a lot of draws, although you never know.
"But these three games before the split are very, very important.
"It would be great for us to stay unbeaten and pick up a couple of wins along the way that would put us in a really strong position."
The 21-year-old added: "Inverness and Ross County are going to have a tough test between themselves and we have a tough test here against Hibs.
"I saw the Edinburgh derby and there was maybe not much in the game but I expect tomorrow to be a very tough test.
"They beat us with a high score (4-0) here last time which was totally undeserved.
"I'm happy with the way we went there and got the comeback win against them, but it's been good games between us and I'm really looking forward to it."